The world's most perfect calibration instrument cannot measure how our brain interprets what our eyes see. Some attempts have been made to emulate how humans perceive light but science has yet to produce an instrument which tells the whole story.

SMPTE's human factors work resulted in their Recommended Practices document RP166-1995: "Critical Viewing Conditions For Evaluation Of Color Television Pictures." This is the work from which D65 bias lighting is taken. The document actually devotes much more attention to color perception than eyestrain. Here are some links that dramatically demonstrate how ambient lighting and surrounding surface colors in the room can cause us to think we see better black levels, enhanced contrast, and/or perceive distorted colors that aren't really in the image.

http://www.echalk.co.uk/amusements/OpticalIllusions/illusions.htm (Note particularly the "Colour perception" and "Colour perception 2" demonstrations.)

http://www.lottolab.org/articles/illusionsoflight.asp (Note particularly the "Brightness illusions" and "Colour illusions")

Professional monitor environments (where critical image analysis is conducted for mastering video programs) use tightly controlled lighting and neutral colored surfaces surrounding the display. The demonstrations above make very clear the importance of incorporating similar room conditions, if image fidelity is desired. This material also makes abundantly clear how destructive to image fidelity the Philips 'Ambilight' colored light features and similar gimmicky fads really are.

Human visual perception is seldom sufficiently understood when consumer display systems (and even many professional ones) are designed and implemented. Since our human vision is so adaptive, we can think we perceive a "natural looking" image but actually don't, if viewing environment conditions are incorrect. The demonstration material at the links above should provide considerable practical reinforcement for folks who have a hard time being persuaded by imaging science theory alone, or even the decades of proven imaging industry professional practice.

If you think there is some trick being used in the online images, try printing out the colored demonstration patterns and making your own paper masks. You will see that the only "trick" involved is being provided by your own brain. This is why even a perfectly aligned display device can indeed look different than a calibration report says. Conflicting viewing environment conditions, such as the wrong lighting or colored room surfaces within the observer's field of view, will ALWAYS distort how a video image appears to the viewer. No calibration instrument can measure this function of the brain. It's simply a perceptual issue.

If a consumer cares about achieving the same "look" of a video program in their home that the mastering technician enjoyed, calibrate the display, and emulate the viewing environment conditions professionals consider best practices. I like to think of this extra effort as fidelity insurance.

Here's a white paper discussing these issues and how they can be incorporated into designing good viewing systems: http://www.cinemaquestinc.com/ive.htm .

Best regards and beautiful pictures,
G. Alan Brown, President
CinemaQuest, Inc.
A Lion AV Consultants Affiliate

"Advancing the art and science of electronic imaging"

Truly amazing demonstrations! They really show the importance of the viewing environment. I put together a simple mask for the top and bottom of my screen for my front projector. I just wrapped styrofoam with black felt and velcroed it to the screen. It makes a big difference.

I am getting ready to put up fabric in my theater room. Right now I have linacoustic (black)on the walls. I would guess that using a neutral gray color would be more appropriate than a deep red or other color. It seems like a lot of people try to create a room that has more impact with the lights on than off.

Anyway, thanks for the demos.

Angryht,

I would guess that using a neutral gray color would be more appropriate than a deep red or other color.

I don't think you're "guessing," but instead arriving at a logical conclusion, founded upon your understanding of simple imaging science principles. However, front projection environments have unique characteristics, different from free standing and direct view type displays. Dark, nearly neutral colors can be OK for front projection theaters. Vivid colors should be avoided, except as minimal accents. It's essential to keep in mind that light can bounce back to the screen from room surfaces, thereby contaminating the image being projected.

It's also important to understand that what is "more appropriate" depends upon your design goals for the system. This section of the forum is dedicated to display calibration. I'm inclined to assume that anyone reading this section is primarily interested in image fidelity and display accuracy. To achieve those interests requires that we follow certain rules, the same rules followed by program producers.

Motion imaging industry standards organizations, such as SMPTE, set the rules. Compromises must be weighed against design priorities. If image fidelity is the top priority, room decor must follow imaging science, rather than aesthetic preference. Providing a flat black ceiling in a front projection theater is a good example. Black ceilings are usually not a hot item to interior decorators.

It seems like a lot of people try to create a room that has more impact with the lights on than off.

You're right, a lot of people do. A lot of people are oblivious to the term 'image fidelity,' including some system designers. Such people have every right to use whatever design priorities they consider "more appropriate" for their lifestyle and how they plan to use the room. Many homeowners want to show off the room with all the lights on more than they want image fidelity when the display is used. Such consumers typically don't take an interest in display calibration.

If image fidelity is most important, don't base your plans for a dedicated theater design upon magazine photos or anyone's opinion. The foundation of reference display system design must be imaging science. Award winning home theaters are usually judged by how the room looks in photographs, with all the lights on, rather than how the system performs. Be clear about your priorities, keeping in mind that any element in the system design which diminishes picture and sound fidelity reduces the value realized from the equipment, the programming purchased, and the time devoted to their use.

I've been in several public theaters and a couple of private home theaters with the lights on that had Burgundy or blue curtains, white ceilings and multicolored floors. with all the lights off except the screen it was impossible to tell that they were any color but black. with the lights on they were aesthetically pleasing and with the lights off PQ was just as pleasing to my eyes.

Image fidelity has nothing to do with pleasing the audience's eyes and everything to do with preserving what pleased the program producer's eyes. It's all about the art. The consequences of a white ceiling in a front projection theater include compromised contrast and diminished color saturation.

I love reading George's posts and his demand for accuracy, it gives me constantly renwed faith in humankind!

I love reading George's posts and his demand for accuracy, it gives me constantly renwed faith in humankind!

And I'm learning just how stealthily the wrong "visual acoustics" can diminish the viewing experience. Watching the same movie under morning daylight conditions and then in evening daylight conditions may actually alter the emotional experience one has with the movie. No wonder my narrow-minded friend saw no value in calibration of his dad's TV's user controls. Still, I think he needs to see something that few people get to see, and is kinda hard to arrange: An identical model of his TV - properly calibrated - sitting next to his factory adjusted set.

It makes me want to repaint the walls behind my TV and behind my couch a nice medium shade of gray....


;)

People have been inquiring about where to get the SMPTE RP166-1995 document mentioned above. This technical reference is available from the Society Motion Picture and Television Engineers directly at: http://store.smpte.org/product-p/rp%20166-1995.htm .

Half the cost can be saved by getting the Widescreen Review back issue of their special edition titled, 'Imaging Science Theatre 2000' from 1998, which includes a reprint of the document,with SMPTE's permission: http://cinemaquestinc.com/isf-mag.htm . This special edition of around 400 pages also includes much more detail about display viewing environment conditions and imaging science principles. It should be in the library of anyone serious about ultimate video quality and display standards.

No wonder my narrow-minded friend saw no value in calibration of his dad's TV's user controls. Still, I think he needs to see something that few people get to see, and is kinda hard to arrange: An identical model of his TV - properly calibrated - sitting next to his factory adjusted set.

Don't be too hard on your friend. We all have narrow and broad mindedness, just on different subjects. Each of us are entitled to our own set of priorities and preferences. I constantly endeavor to guard against dogmatism. Image fidelity is simply not a top priority for many people. My intent is to educate and confront wrong information, misunderstanding, and confusing industry practice, by using reference standards, imaging science, logic and reason.

We all come from the factory with differing aptitudes, preferences, inclinations and talents. Some people will never be persuaded, even by demostrations and logic. They just don't 'get it' and never will. Concentrate on those who express an interest in what you have to offer. Your capacity for persuasion has limits, and those limits are often times totally outside your control.

Best regards and beautiful pictures,
G. Alan Brown, President
CinemaQuest, Inc.

"Advancing the art and science of electronic imaging"

It makes me want to repaint the walls behind my TV and behind my couch a nice medium shade of gray....

Many folks are put off by the thought that their room could end up looking like a battleship, with medium gray walls. For self-contained video displays, only the area surrounding the TV (within your field of view while watching the screen) needs to be neutral colored. White is also neutral. Neutral colored patterns, wall hangings, and/or textures can be incorporated to add interest.

The wall opposite the TV does not have to be gray either. SMPTE's recommendations also allow for nearly-neutral colors to be used elsewhere in the room.

Nice thread George!

sticky :)

Thanks for the links GeorgeAB, very enlightening.

And I can now better understand what you mean about a yellow wall (or in my case yellow/gold pattern wallpaper) behind a plasma being bad for viewing.

I have seen the light (pun intended), & plan on utilizing a light-to-medium gray paint to the brick wall behind the plasma of our most recently purchased home.

Does a black bezel around a plasma create problems? Would it be better if it was gray as well? [I'm not suggesting to change my plasma, just curious].

Black is usually very neutral. I personally find the high gloss black frames a distraction, since they act like mirrors. The early digital TVs had silver or gray frames and cabinets to call less attention to the poor black levels on the screen. This has improved over the years and manufacturers are more confident about surrounding the image with a black border. If I had a gloss black frame I would cover it with black Duvetyne tape.

The National Institute for Standards and Technology (NIST) has labs near me in Boulder, CO. They have assigned one of their physicists to evaluate methods to help professionals and consumers select the right flat panel display for a given application. One very big factor that was considered is the impact the display's environment has upon the picture. NIST provides a nifty tutorial on their web site to illustrate how different flat panel display types handle various viewing environment challenges. Here's the link to the tutorial: http://www.fpdl.nist.gov/tips.html . It features a PDF slide show that you can save in a file. Many of the images are very good examples of the kinds of interferance to picture quality that poor viewing conditions can present.

Here's a link to a recent article in the Rocky Mountain News featuring an interview with the man who runs this department at NIST's Boulder labs: http://www.rockymountainnews.com/drmn/tech/article/0,2777,DRMN_23910_5558486,00.html . This newspaper article will only be available for a limited time.

The newspaper article link above was defective. I have repaired it. Sorry!

Here's another reference for calibrators and hobbyists interested in professional documentation of international standards for display viewing environment theory and practice.

ITU-R BT.710-4 "Subjective Assessment Methods For Image Quality In High-Definition Television,"

To order via Word document or PDF download: http://www.itu.int/rec/R-REC-BT.710-4-199811-I/en

Best regards and beautiful pictures,
Alan Brown, President
CinemaQuest, Inc.

"Advancing the art and science of electronic imaging"

Here's a recent article that looks at the effects of ambient lighting upon color perception and contrast in flat panel TV environments: 'Illumination and Displays: Color Appearance of a Display Changes Under Various Illumination Conditions'

http://spie.org/x13920.xml?highlight=x2408

The article is from SPIE: an international society advancing an interdisciplinary approach to the science and application of light (formerly: The International Society for Optical Engineering). There are plenty of interesting links on their web site for more data on electronic display viewing environments and human visual perception.

Truly amazing demonstrations! They really show the importance of the viewing environment. I put together a simple mask for the top and bottom of my screen for my front projector. I just wrapped styrofoam with black felt and velcroed it to the screen. It makes a big difference.
Absolutely agree.
When my clients ask me what is the best color for their Home Theater with front projector, my answer is: Flat black everywhere but screen. (Just for dedicated HT not a play room with pool or other toys)
They look at me with big skepticism.
I explain, make demonstrations and they are still not convinced. The only black HT I know was in my house I just sold.
Did I persuade even one client so far? No!
(however recently one decided to go with charcoal carpet and gray walls and ceiling).

I am getting ready to put up fabric in my theater room. Right now I have linacoustic (black)on the walls. .
My advice: If this is dedicated HT - stay with black.

It seems like a lot of people try to create a room that has more impact with the lights on than off.
That’s right and this trend is stimulated by media. Look at “samples” or “suggestions” in Audio Video Interiors and other related to audio video magazines.

I've been in several public theaters and a couple of private home theaters with the lights on that had Burgundy or blue curtains, white ceilings and multicolored floors. with all the lights off except the screen it was impossible to tell that they were any color but black.
It is possible only when there is no light from the screen. During bright scenes you can definitely see all details, colors etc around you. Light reflected from walls, ceiling and other objects goes back to screen changing picture. Links presented by Alan are the best proof.
If you want fidelity - burgundy walls are not an option.

That’s right and this trend is stimulated by media. Look at “samples” or “suggestions” in Audio Video Interiors and other related to audio video magazines.

Excellent point. I think it's great to have a room to show off the interior decoration skills of the owners, but I think more emphasis needs to taken when the lights are off. That said, however, not everybody wants a 'bat cave' environment to watch movies, but they should!

The only black HT I know was in my house I just sold.

Any pics? Did you use fabric (GOM) or paint? Just looking for ideas (oh yeah, and motivation - kind of tough for me to focus on aesthetics when trying to get sound and picture fidelilty correct).

Excellent point. I think it's great to have a room to show off the interior decoration skills of the owners,
They have a lot of places to do so: Dining, living, family room, kitchen etc.
but I think more emphasis needs to taken when the lights are off. That said, however, not everybody wants a 'bat cave' environment to watch movies, but they should!
I had problem with my wife in the beginning, but I said that in this one room I decide about décor. Some times later after we saw several movies, she said that I was right, that picture and sound are MUCH better than before.

Any pics? Did you use fabric (GOM) or paint?
Sorry, no pics. It is very difficult to make pictures when everything is flat black. (maybe this is the reason we don’t see black HT in magazines) I used fabric on walls, carpet on the floor and black 2x2 panels on the ceiling. Door inside, baseboard and trim was painted.
Just looking for ideas (oh yeah, and motivation - kind of tough for me to focus on aesthetics when trying to get sound and picture fidelilty correct).
Send me e-mail so we can discuss it over e-mail.

Here's a neat trick for folks who balk at the bat cave concept. Use darker shades of gray, rather than black, especially on the front and side walls. Illuminate the neutral gray portions with soffited or baffled colored lights. The lights will turn the gray portions of the room any color you want. This gives unlimited color choices for the designer to use when the lights are on in the room. Darker shades of gray are very nearly as effective as flat black during the showing of the movie.

More colored light options are appearing on a regular basis with LED arrays. In fact, the red/green/blue arrays can be controlled electronically to produce just about any color in the spectrum. Conventional white lights can be added for times when the room must be navigated in or for cleaning.

The LED arrays would offer automated color schemes that could be changed with mood or theme. How about green, prior to showing 'The Matrix' films. Blue could be used prior to 'The Terminator.' Red would be appropriate prior to a Dracula flick. The options are only limited to the owner's imagination.

Best regards and beautiful pictures,
G. Alan Brown, President
CinemaQuest, Inc.

"Advancing the art and science of electronic imaging"

Concerning back lighting, does it make a difference how far from the edges of the set the lighting extends?

For example, if you could back light just a 1' area around the set, would that work as well as say an area 5' around the set?

tia

I expect one foot is still sufficient to provide the intended benefits. This may limit the benefit at wide horizontal viewing angles for other seating locations (depends on whether the TV cabinet is very deep).

Gotta it, thx George.

Here are two linked articles discussing display viewing environment principles at the new public ISF Forum site:
http://www.isfforum.com/FAQs/view/ISF-Video-Calibration/Why-is-the-Viewing-Environment-Important/33.html
http://www.isfforum.com/index.php?option=com_deeppockets&task=catContShow&cat=16&id=51&Itemid=48

Best regards and beautiful pictures,
G. Alan Brown, President
CinemaQuest, Inc.

"Advancing the art and science of electronic imaging"

Excellent resources. Thanks, George.

The second link listed above is temporarily non-functional due to some updates and edits being done by the isfforum.com admin. I'll let this thread know when the article link is working again.
Here's a temporary replacement for that link: http://cinemaquestinc.com/ive.htm . It's a white paper with the same info, just more technical in format.

The link in post 26 has been repaired.

I just got my ideallume backlights and installed them. I haven´t yet calibrated the backlights but I dimmed them down pretty much all I could. I only have a 32" and I still get tons of backlight. Gonna get DVE to try and calibrate it a bit.

So far for sure it´s different but can´t say yet if it´s for better then for worse lol. Feels like the image somewhat feels brighter then before due to the backlight which I thought would be the other way around? I feel the need to reduce the brightness on the television however my Sony 32 inch bravia is a SPVA panel and tend to loose details in the blacks so will see how that turn out.

I also use the tv as computer monitor so it being better for the eyes is a big plus if it turns to be true lol.

However how important is it to have the right colour on the background. I am not absolutely crazy about image quality if I get 90 % of the benefit I am a happy camper... The wall is kind of a very light blue colour so not optimum I guess if I read the manual correctly. Though it´s not all that far from grey after all. It´s not that clean too with cables and stuff but don´t think that matters that much. 2 ideallumes is more then enough for my 32" it seems :)

As for colours I think you can adjust the colour rating on your tv? Should I set it to 6500 too if it isn´t already not sure...

I just got my ideallume backlights and installed them. I haven´t yet calibrated the backlights but I dimmed them down pretty much all I could. I only have a 32" and I still get tons of backlight. Gonna get DVE to try and calibrate it a bit.
That's a lot of light for such a small TV. However, LCDs tend to run brighter and you may end up needing the extra illumination to put the right amount of illumimation on the wall (10% of peak white). Another way to reduce the light, after rotating the baffle tubes all the way around, is to rotate the whole fixture around to block more light from reaching the wall.
Feels like the image somewhat feels brighter then before due to the backlight which I thought would be the other way around?
If you mean versus having the room lighting on, yes it will likely appear brighter in a darkened room.
I also use the tv as computer monitor so it being better for the eyes is a big plus if it turns to be true
Of course it's true!
Though it´s not all that far from grey after all.
Sounds decent enough for a 90% kind of guy.
Should I set it to 6500 too if it isn´t already
Only if you want better image fidelity.

Best regards and beautiful pictures,
G. Alan Brown, President
CinemaQuest, Inc.

"Advancing the art and science of electronic imaging"

Here's a neat trick for folks who balk at the bat cave concept. Use darker shades of gray, rather than black, especially on the front and side walls. Illuminate the neutral gray portions with soffited or baffled colored lights. The lights will turn the gray portions of the room any color you want. This gives unlimited color choices for the designer to use when the lights are on in the room. Darker shades of gray are very nearly as effective as flat black during the showing of the movie.

More colored light options are appearing on a regular basis with LED arrays. In fact, the red/green/blue arrays can be controlled electronically to produce just about any color in the spectrum. Conventional white lights can be added for times when the room must be navigated in or for cleaning.

The LED arrays would offer automated color schemes that could be changed with mood or theme. How about green, prior to showing 'The Matrix' films. Blue could be used prior to 'The Terminator.' Red would be appropriate prior to a Dracula flick. The options are only limited to the owner's imagination.

Best regards and beautiful pictures,
G. Alan Brown, President
CinemaQuest, Inc.

"Advancing the art and science of electronic imaging"

A little like this:

http://gallery.mac.com/kipnis#100013

Cheers -

Jeremy


www.Kipnis-Studios.com

Here's another example: http://www.tktheaters.com/gallery/parkavenue/

I think it very important to stress these lighting schemes are kind of cool prior to the movie and not during! But, then again, I suppose that is covered in the title of this thread. Great examples, guys.

Yes, the point is- rooms can be designed to look "cool" when the video system isn't being operated and all the lights are on. When the lights go out and the show begins, the room should disappear. All that is required to reach an acceptable compromise is some fundamental understanding of imaging science principles and a little imagination/ingenuity.

The problem remains that so many consumers, home entertainment contractors, and interior design professionals, haven't realized that correctly performing home theater design isn't "business as usual." Like most pursuits in life, genuine excellence requires education and extra effort. Intuition, whim, fad, fashion, anecdotal experience, uninformed preconceived notions, etc., may suffice for some decisions but not when it comes to conveying image fidelity.

I think some of the pics shown in a lot of the publications do a disservice in these matters, for exactly the points you've been making throughout this thread. They always cut and paste an image on the display they are trying to 'show off' and I think people think that's cool and try to emulate it.

I understand their objectives completely. There is no simple way to convey in a print or online publication how a room performs. Such feature articles focus on what can get folks' attention with a few words and photos. Unfortunately, poor technical design practice gets mixed up with attractive aesthetic priorities.

I'm not dogmatic on this issue. It's perfectly alright to have greater priorities that conflict with image fidelity, as long as the consequences to picture quality are understood and consciously considered acceptable. As an imaging science advocate, my intent is to educate the home theater community about the consequences behind the compromises. When the blind lead the blind, they both can end up where neither really intended.

Yes, the point is- rooms can be designed to look "cool" when the video system isn't being operated and all the lights are on. When the lights go out and the show begins, the room should disappear. All that is required to reach an acceptable compromise is some fundamental understanding of imaging science principles and a little imagination/ingenuity.

The problem remains that so many consumers, home entertainment contractors, and interior design professionals, haven't realized that correctly performing home theater design isn't "business as usual." Like most pursuits in life, genuine excellence requires education and extra effort. Intuition, whim, fad, fashion, anecdotal experience, uninformed preconceived notions, etc., may suffice for some decisions but not when it comes to conveying image fidelity.

Here, Here!

This is why an IMAX or Academy Screening is no guarentee of image or sound fidelity. But they can be some impressive screening conditions when both the archetecture and decor compliment the technology utilized.

Balance and sensitivity are two other key traits I value in my work as a screening and listening room designer.

Cheers -

Jeremy

www.Kipnis-Studios.com

I posted a recent discovery over in another thread, that should be instructive for readers following this discussion: http://www.avsforum.com/avs-vb/showthread.php?p=13966345#post13966345

Best regards and beautiful pictures,
G. Alan Brown, President
CinemaQuest, Inc.

"Advancing the art and science of electronic imaging"

Great stuff, George. Thanks.

Is there a general rule regarding how many light units will be needed to create the ideal amount of lighting?

I have a 42" Vizio XVT and was wondering if one Ideal-Lume standard would be adequate for my setup.

In another room (family members) we have a 58" Panasonic Plasma. Would one Ideal-Lume standard be adequate(I assume not)?

If any one has any information regarding this I would appreciate it.

Daniel

Is there a general rule regarding how many light units will be needed to create the ideal amount of lighting?

I have a 42" Vizio XVT and was wondering if one Ideal-Lume standard would be adequate for my setup.

In another room (family members) we have a 58" Panasonic Plasma. Would one Ideal-Lume standard be adequate(I assume not)?

If any one has any information regarding this I would appreciate it.

Daniel

One Ideal-Lume standard bias light (behind the display) should work for either display. Just because the Panasonic is 58" or is a Plasma will not change the bias lighting requirments - only the amount of light coming from the screen. The brighter (or higher contrast) the image is, the more bias lighting you will require. But first, try adjusting the contrast of each set to be 10 times the bias lighting coming from a single light. This will create the correct proportion of ambient light versus on-screen light levels - thus achieving ideal iris size versus actual in-room light levels.

Thank you for the clarification. The reason I asked was that I saw pictures with as many as 2-4 lighting units on some of the pictures on their website.

Daniel

Thank you for the clarification. The reason I asked was that I saw pictures with as many as 2-4 lighting units on some of the pictures on their website.

Daniel

I'm certain that they would like to sell you as many as possible. And given a specific light requirement (by you) might very well need several of their units.

But . . . many, here on these forums, believe in Cinema light levels which should be 16 foot-Lamberts on a screen whose apparent size fills about 1/3 of your center front vision - this in a dark theater. But the most important part for you is that the light levels from your monitors generate life-like whites while maintaining solid (BUT DETAILED) blacks - this is contrast ratio.

Tell, me . . . with either of these sets, have you had them calibrated or made adjustments yourself to improve the :out of the box" performance?

Daniel,

Jeremy has made some good points. Much depends on how dark the wall is behind the display. This discussion would be more specifically suitable in the sticky thread dedicated to video display bias lighting. There are many other viewing environment issues beyond the scope of that thread topic, which are the focus of this thread. I would also be pleased to handle any specific application questions regarding my products through company phone or e-mail, if you want individual help.

Best regards and beautiful pictures,
G. Alan Brown, President
CinemaQuest, Inc.
A Lion AV Consultants Affiliate

"Advancing the art and science of electronic imaging"

I'm certain that they would like to sell you as many as possible. And given a specific light requirement (by you) might very well need several of their units.

But . . . many, here on these forums, believe in Cinema light levels which should be 16 foot-Lamberts on a screen whose apparent size fills about 1/3 of your center front vision - this in a dark theater. But the most important part for you is that the light levels from your monitors generate life-like whites while maintaining solid (BUT DETAILED) blacks - this is contrast ratio.

Tell, me . . . with either of these sets, have you had them calibrated or made adjustments yourself to improve the :out of the box" performance?

I recently purchased the Vizio 42" XVT and have used the THX calibration for brightness, contrast, and shaprness. The remaining settings I used from CNET's calibration of the 47" XVT.

I did this for AV (DVD player), VGA (Computer), HDMI (Computer).

The 58" Panasonic isn't as new, it was purchased from bestbuy a few months ago and will be calibrated in November as part of the package deal. The 58" is my fathers and has not been touched yet for calibration. I intend to calibrate the brightness, contrast and sharpness with the THX disc to see how close I come to professional calibration.

I am essentially convinced that I would like to setup bias lighting. I am also trying to convince my father it would benefit him. Most of his watching is at night (TV/Movies) with the lights off. I intend to purchase a more thorough calibration DVD possibly DVE blueray, but will wait to see if a PS3 becomes part of my system.

I likely will contact George via email or phone. The main concerns are one unit will being adequate, whether the ideal-lume panel light is essentially two standards(one for me, one for dad).

Attached is a picture of my current setup for the 42". Note that I have not yet adjusted my center speaker from its original position for a 32". I realize my backing isn't ideal with the framing and louvers. I also assume that the speaker sitting on the top of the TV would also prevent the complete surrounding of bias lighting. The center speaker does not support it self, hence leaning on the TV. If required I could make something to support the speaker and raise it above the TV.

Any feedback or suggestions would be appreciated.

Daniel

Thanks, Daniel, for moving your questions to the bias lighting thread.:)

We have a large window one side of the living room and finally convinced my parents to buy some kind of black out shade for it. I took them to blinds to go and they would like to buy a blackout roller shade. They would prefer to buy from blinds to go because they have a friend there. I have a couple of questions.

1. They want an inside mount only. The problem is, there are 0.5 inch gaps on each side. Will that significantly affect our viewing area?

2. We have a choice on color for one side (the side that will be facing the living room) to be any color we want. Would colors such as brandy cream be ok to put up or would a neutral color be better (solid white, black, or grey). I think they would prefer something a little more "lively" than the latter.

Relative to N,S,E,W, the window is on the W while the TV is on the N wall. Thanks in advanced.

The half inch gaps should not be very problematic although not ideal.
The wall behind the TV is of primary concern for color. Choose a color as close to neutral as possible. A vivid color would be most undesireable for best color perception from the TV image. The other colors in the room would be best subdued rather than vivid. A wall directly opposite the TV should be darker, as much as possible. Multi-use rooms are commonly a challenge when designing a color scheme for non-TV use.

The Color of the wall behind the TV is white which I think is fine. This is a living room/family/movie watching room so I don't really have control over the color of the walls. Do you have any suggestions for inside mounts that do not have gaps? Preferably something that gives us the ability to still see through the window. I've seen a couple of pictures on this website where people compeltely covered their windows with fabric or garbage bags but I don't think my parents would like that idea. If nothing, I guess these rollers would do.

Roller shades are quick, easy and inexpensive. You could put trim moldings on either side of the window jambs, painted or stained to match. They would serve as baffles for blocking the light leakage. Other options from window shade boutiques offer tracks that a matching shade runs in for total light seal. They are much more expensive.

when setting the 10% of light using the dve disk will it work for both lcd and plasma, cause i have both. Also on that subject i find that trying to match the grey shown on the pattern and the shade on the wall is really hard to be accurate given that it has to be done visually and not with specialized equipment.
Another thing that im confused with is the possibility of placing two idealumes instead of just one in the back of my lcd. This tv is made to be wider than the normal flat panel tv, its a 40 incher. So the reasult is that i dont get as much light coming from the sides of the tv. Though i do get more than enough light coming from the top and bottomof the tv.
Judging from the pictures provided by the other idealume owners on this site it seems that they are getting an equal amount of light output behind the tv reflecting on the wall, like 2 to 3 inches of light all around the tv in a straight line. What i get is light start of bright than starts to fade slowly not abruptly like the other examples mentioned above. I dont know if im describing this effect the best i can, but think of two different frames and the tv being the picture in the frame. Mine looks like a circular frame and the other settups look like rectangular frames having 2 to 3 inches equally on all four sides.
I dont know why i cant make it look like the others?

when setting the 10% of light using the dve disk will it work for both lcd and plasma, cause i have both.
It will work in every case where both video and human vision are used together. The type of display is doesn't matter.
Also on that subject i find that trying to match the grey shown on the pattern and the shade on the wall is really hard to be accurate given that it has to be done visually and not with specialized equipment.
Such a degree of accuracy is not necessary. Your visual judgement is sufficient for the procedure. The similar pattern on the 'Avia Guide to Home Theater' or 'Avia II' DVDs may work better for you.
Another thing that im confused with is the possibility of placing two idealumes instead of just one in the back of my lcd. This tv is made to be wider than the normal flat panel tv, its a 40 incher. So the reasult is that i dont get as much light coming from the sides of the tv. Though i do get more than enough light coming from the top and bottomof the tv.
Judging from the pictures provided by the other idealume owners on this site it seems that they are getting an equal amount of light output behind the tv reflecting on the wall, like 2 to 3 inches of light all around the tv in a straight line. What i get is light start of bright than starts to fade slowly not abruptly like the other examples mentioned above. I dont know if im describing this effect the best i can, but think of two different frames and the tv being the picture in the frame. Mine looks like a circular frame and the other settups look like rectangular frames having 2 to 3 inches equally on all four sides.
I dont know why i cant make it look like the others?
Such a degree of uniformity is not necessary. How the illuminatiion distributes on the wall is determined by many various factors: size and shape of the TV cabinet, how far from the wall the bias light happens to be mounted, whether it's vertical or horizontally oriented, how the rotating baffle tube is adjusted, whether or not the light fixture is also rotated, how parallel to the wall the back of the TV cabinet happens to be, how reflective the wall surface is (ie: glossy vs matte finish), etc. I suspect you may have the TV too close to the wall. Try moving it a bit farther away. Don't try to match other people's photos unless you think your system is completely identical to theirs.

It will work in every case where both video and human vision are used together. The type of display is doesn't matter.

Such a degree of accuracy is not necessary. Your visual judgement is sufficient for the procedure. The similar pattern on the 'Avia Guide to Home Theater' or 'Avia II' DVDs may work better for you.

Such a degree of uniformity is not necessary. How the illuminatiion distributes on the wall is determined by many various factors: size and shape of the TV cabinet, how far from the wall the bias light happens to be mounted, whether it's vertical or horizontally oriented, how the rotating baffle tube is adjusted, whether or not the light fixture is also rotated, how parallel to the wall the back of the TV cabinet happens to be, how reflective the wall surface is (ie: glossy vs matte finish), etc. I suspect you may have the TV too close to the wall. Try moving it a bit farther away. Don't try to match other people's photos unless you think your system is completely identical to theirs.

the tv is not in a cabinet and its 3 to 4 inches from the wall. i have it placed horizontally across the back of the tv at exactly the center point of the tv, by measurements, and the filter is also rotated in the canter. I also have a second idealume in hand and i dont know if its a good idea to place both side by side to help get some light on the sides of the tv, because of the wideness of the my panel i dont get as much light from the sides.

the tv is not in a cabinet and its 3 to 4 inches from the wall. i have it placed horizontally across the back of the tv at exactly the center point of the tv, by measurements, and the filter is also rotated in the canter. I also have a second idealume in hand and i dont know if its a good idea to place both side by side to help get some light on the sides of the tv, because of the wideness of the my panel i dont get as much light from the sides.
I was refering to the TV's own cabinet, not implying that you placed it into an entertainment center or additional cabinet. Just try the additional light behind the TV, if you are reluctant to move it out from the wall farther.

just so i know what is the optimal distance to have between the bias lamp and the wall, like i said i have it at around 4 inches right now.Is it not enough?
would nt two lights be overkill? What the best case scenario?

just so i know what is the optimal distance to have between the bias lamp and the wall, like i said i have it at around 4 inches right now.Is it not enough?
would nt two lights be overkill? What the best case scenario?
Optimal distance is for you to determine.
Whether two lights would be overkill is for you to determine.
The best case scenario is for the illumination on the wall to surround the TV screen evenly and the general level of brightness on the wall to be 10% or slightly less of the brightest white the TV produces after adjusting the picture for dark room viewing.

One question. The walls at our home are white. But How do I know if I have the right shade of white?

The simple way is to compare the paint on the wall to a known reference under the same lighting you'll use during viewing of the display. I suggest using a Munsell Neutral Value sample for specifying, matching, and judging neutral paint colors: http://www.cinemaquestinc.com/ideal_viewing.htm . The Munsell Color Order System is the method used by SMPTE for specifying color. Most residential applications wouldn't require absolute precision but it's not really very expensive or difficult to achieve reference quality viewing environment conditions in the home. The greatest obstacle for most people is simply not understanding the principles involved.

Hello,

I will soon be getting my 63" samsung plasma and will be getting it ISF calibrated.

The walls in my 'theater room' are light, desaturated blue (wifes choice, not mine). The blue is an even lighter shade than that used on this site. I don't think its too bad, but if I can achieve the correct 6500k backlight color that would be ideal.

is there a backlight out there that can compensate for this by going a bit more warm than 6500k? I saw talk of LED backlights in the locked thread, but could somebody please fill me in on what products are out there or how I could compensate for slightly blue walls?

Thanks alot
Ryan

You would need to try various lamps of a lower color temperature or apply colored filters to color correct the wall. In addition, you would need a color analyzer to confirm when you achieve CIE D65 or 6500K. If you want to eyeball it and just guess, try starting with a 5000K fluorescent with a high color rendering index (CRI). If your TV is calibrated, it could be used as a reference for comparing the color of illumination being reflected from the wall.

Wouldn't it be much more simple to paint just the wall behind the TV a complimentary shade of neutral gray or white? Neutral gray will not conflict with any other color in the room, even if the whole color scheme in the room is changed to redecorate. Then the TV will look more correct even when the room lights are on or the windows coverings are open during the day.

We are looking into an RGB LED solution that may have the fine adjustment capability that would enable calibratiion to compensate for non-neutral wall colors. This could be adjusted at the same time the TV is calibrated. It won't be inexpensive.

Best regards and beautiful pictures,
G. Alan Brown, President
CinemaQuest, Inc.
A Lion AV Consultants Affiliate

"Advancing the art and science of electronic imaging"

Thanks for the reply.

I might be up for some DIY LED projects.

(check out these LED arrays I made for my reef tank: http://www.worstkind.com/aquarium/2009/0502/leds01.jpg )

Question with LEDs in this application is how to diffuse the light evenly? I assume side emitting would be better than lambertian? And if so I'm not sure how a collimator type optic would be able to evenly blend RGB??

Interesting topic for sure.

Thanks
Ryan

Wouldn't it be much more simple to paint just the wall behind the TV a complimentary shade of neutral gray or white?

not if you saw the look on my wife's face when I mentioned this hypothetical solution :D

Question with LEDs in this application is how to diffuse the light evenly? I assume side emitting would be better than lambertian? And if so I'm not sure how a collimator type optic would be able to evenly blend RGB??

That's one reason why fluorescents are still superior for many applications. They are naturally very diffused and offer high light output at relatively low cost.
not if you saw the look on my wife's face when I mentioned this hypothetical solution
How much education was the mention preceded by? Women are biologically more sensitive to color differences than men. They can obsess over the subtle differences in shades of pink lipstick or shades of brown hair color. The fashion and makeup industries know well how certain colors of their products can be unflattering alongside various colors of complexion and hair. These issues are not necessarily instinctive or intuitive for women. They still must be taught the principles involved to be fully aware.

I'm not really very surprised when anyone fails to see the importance of viewing environment conditions in a video system. It seems to be the last element of good system design to be genuinely comprehended or valued, even by some ISF and THX grads. Human perceptual factors make the viewer as much a component in the system as any other element, and thereby the room conditions.

Good point. I didn't really go into detail explaining it.... In fact she was already a bit annoyed that I spent all weekend reading the AVS forums :D

We only just had the room painted a week ago so maybe she just needs time to enjoy it first :) shes not very picky when it comes to picture quality like I am so I don't think a technical explanation will work. She will just use the generic "you're overthinking it" response :)


....BUT, I think a neutral grey wall would look cool there.... I might resort to a 3D-rendering mockup since in my experience showing her something is a much better method of persuasion than trying to explain something technical.

Thanks again.

Is there a way to calibrate the 10% light output using the AVS HD 709 dvd/mp4?

GeorgeAB,

I wasn't able to convince my wife we needed a white or gray wall behind the TV.... however I did do some 3D mockups and she liked the look of a white acrylic panel behind the TV, about 12" bigger in all directions (kinda integrates with the 'modernish' cabinets that will surround the TV).

Do you think having a foot-wide white border would do much? This acrylic panel could easily house a light behind it at night to make a neutral gray backdrop.

That sounds like it could be beneficial. I'm not confident I understand fully how this would be implemented, though.

maybe its a bit bizzare but this is the general idea.

http://www.worstkind.com/backlight.jpg

I have some spare 6500k CREE Q5 LEDs from a recent project and a local acrylic shop that cuts to size so it should be fairly quick to prototype. probably easier with fluorescents though. But for the LEDs there are some fairly cheap elliptical optics out there to try (46 x 9 degree).


The powersource would be wired to a potentiometer to tweak the brightness.
Sorry don't mean to derail the thread too much into DIY.

It looks workable. Have fun.:)

maybe its a bit bizzare but this is the general idea.

I have some spare 6500k CREE Q5 LEDs from a recent project and a local acrylic shop that cuts to size so it should be fairly quick to prototype. probably easier with fluorescents though. But for the LEDs there are some fairly cheap elliptical optics out there to try (46 x 9 degree).


The powersource would be wired to a potentiometer to tweak the brightness.
Sorry don't mean to derail the thread too much into DIY.

I was thinking of the same thing but with black. I'd like to use something to surround the TV without painting. Just haven't figured it out yet. So I guess shivers are running threw spines right now with my color scheme but I like the Tuscan look and the real color is no where near the orange you see here.

http://www.reprovideo.com/tvnbl.jpg

http://www.reprovideo.com/tvbl.jpg

So would this work or is my color choice on the walls too overpowering?

It's usually hard to illuminate black. The wall color interference will be reduced by your attempted surround treatment nearer the display.

The use of the technique of bias lighting has the perceptual effect of improving the contrast performance of televisions. Improved contrast in an image also has the beneficial effect of making the image appear to have greater sharpness.

I was reminded of these benefits while reviewing an article from the 'SMPTE Journal,' November of 2002. The title of the article was 'The Importance of Contrast and its Effect on Image Quality' by Segler, Pettitt and Kessel. Here are some pertinent quotes from the article:

"Contrast could be considered to be the most significant quality that impacts not only the perceived depth of an image, but also affects the apparent sharpness.....While the luminance level of a given image affects how the eye perceives contrast and detail, the ambient conditions surrounding the image can also have a dramatic impact. This phenomena was studied by Bartleson and Breneman (1967) to examine the impact of perceived contrast based not only on the luminance level of the image but taking into account the surrounding ambient luminance levels as well. Their results showed that the perceived contrast increased as ambient luminance increased. With the increase in ambient luminance, the eye interprets black levels as being darker while the impact to the white level is minimal. Since the perceived difference in dark areas is greater under the higher ambient luminance conditions, the perceived contrast is higher. It is a natural tendency to want low ambient luminance levels to strive for "better" perceived image quality and what is thought to result in higher contrast. However, in reality, the opposite is true. This tendency may be justified for current direct view CRT televisions due to the issue of glare that results from the glossy surface of the glass tube [also true for certain flat panel displays today]. With less ambient luminance, the glare is reduced- but it may be important to keep some ambient luminance behind the television [as in the case of bias lighting] to keep the perceived contrast higher.....While sharpness can affect the apparent contrast of an image, the converse is true in that contrast can also impact the apparent sharpness of an image. Images that have lower contrast will appear to be not as sharp as an image of the same content, but with higher contrast.....A subjective study was then conducted to verify the impact that ambient lighting has on perceived contrast. Several non-technical (and thus presumably non-biased) and technical observers were asked to compare a series of images with various ALL [average luminance levels] under different ambient luminance extremes in order to understand the impact that ambient viewing conditions might have on the perceived contrast between the two television technologies [CRT and DMD (DLP RPTV)]. Under dark ambient conditions, the result for images with an ALL > 5% was found to be equal between the CRT and the first DMD display. However, under bright ambient conditions (about 250 nits of luminance on the wall behind all of the units), the DMD display was favored over the CRT by 50% of the observers as having higher perceived contrast.....This proved that ambient conditions have the effect of potentially raising the black level threshold of the eye above the actual black level of the television such that the perceived contrast ratio is higher."

Here's another related reference from: 'Color Appearance Models,' by Mark D. Fairchild, Ph.D., of the Chester F. Carlson Center for Imaging Science: Munsell Color Science Laboratory.

"Their experimental results, obtained through matching and scaling experiments, showed that the perceived contrast of images increased when the image surround was changed from dark to dim to light. This effect occurs because the dark surround of an image causes dark areas to appear lighter while having little effect on light areas (white areas still appear white despite changes in surround). Thus since there is more of a perceived change in the dark areas of an image than in the light areas, there is a resultant change in perceived contrast.....Often, when working at a computer workstation, users turn off the room lights in order to make the CRT display appear of higher contrast. This produces a darker surround that should perceptually lower the contrast of the display. The predictions of Bartleson and Breneman are counter to everyday experience in this situation. The reason for this is that the room lights are usually introducing a significant amount of reflection off the face of the monitor and thus reducing the physical contrast of the displayed images. If the surround of the display can be illuminated without introducing reflection off the face of the display (e.g., by placing a light source behind the monitor that illuminates the surrounding area), the perceived contrast of the display will actually be higher than when it is viewed in a completely darkened room."

Best regards and beautiful pictures,
G. Alan Brown, President
CinemaQuest, Inc.
A Lion AV Consultants Affiliate

"Advancing the art and science of electronic imaging"

Good news: I received my Ideal Lume Panelight! So excited to put it on.

Bad News: One of the components is broken. I believe it goes onto the light itself but I am not sure what it does. What does it actually do and is it important?

In any case, I will be emailing to let them know and hopefully get another one soon.

Sorry about the problem. Please e-mail your order info to our office. We'll file the shipping damage claim for you and send out what was broken tomorrow. Hang on to the original packaging in case the UPS driver wants to inspect it.

Oh, yeah. We'll need to know what was damaged, as well.

Here's a neat optical illusion that graphically illustrates how adjacent colors can skew our color perception: http://www.avsforum.com/avs-vb/showthread.php?p=16766171#post16766171 .

Long time lurker second time poster. First off good information guys, always good to get my knowledge on this kind of stuff up.
Secondly im from New Zealand and was wondering if anyone knew of any places in New Zealand where i could buy any of the aforementioned lighting sets. I've searched everywhere to no avail. Any help is greatly appreciated.

My company has shipped to customers in NZ in the past but the power system is different, requiring a voltage converter. There should be the basic component parts in your country or available online from a vendor closer to you than the US. Just look for high CRI fluorescents at 6500K.

I have yet to test any commercially available white LEDs closer than 7500K, even when the provider claims 6500K. One recent sample (last week) of white LED rope light was from a company that emphatically insists their diode supplier gives them LEDs that are between 6000K and 6500K. I ordered a sample and measured it with my spectroradiometer under controlled conditions. It measured at 8000K.

George,

I am uncertain whether I will put the Pioneer 500M on a stand about 5 " from the wall or on the wall mount.

If I get the panellight to allow for the latter situation, can the amount of light being displaced be controlled so as to be able to use it if I choose to mount away from the wall?

I have this color behind the TV: http://www.icipaints.co.uk/servlet/ColourSchemeHandler?name=30bb_16031

The rest of the room is this color: http://www.thegrovefurniture.com/gf018.html

The ceiling remains white though I do have a large Oatmeal acoustic panel that I could put up inbetween the TV and the seating area which would prevent direct reflection from overhead.

I hope this makes sense :)

I have a calibration coming up in a week or so and I want to have all the pieces in place ready for that day (I don't actaully have the TV yet - Monday).

Sincerely,

Morris

Personally, I consider wall mounting of flat TVs to be a fad that results in compromised viewing conditions for most people. Bias lighting with the Ideal-Lume Panelight product can be used in either case, but is less easy to get even distribution with wall mounting. Your color scheme looks fine. Be sure to use a matte finish. You are welcome to contact the company directly if you need any additional assistance.

Thank you George. Flat Matte finish used and panelight on the list of things to order.

forever....

your place is fantastic. I really like the "look" and "feel" of it. Must be a very relaxing and constructive space to record in. I would think yours to be a model of what home reccors could do with their setups.

Can someone explain exactly what the "baffle tube" looks like to adjust the blockage of light? Is it the thin black strip that is inserted into the tube with the bulb? If not, I think it may have not been shipped.

Here's a quote from the info sheet included with the product: "Ideal-Lume’s output can be reduced by simply rotating the included light baffle tube around the lamp." The baffle tube is shipped already in place around the fluorescent lamp. If it's not there, that would be highly irregular, but not impossible.

Q: If I don't have any eye strain issue with dark room viewing, is it still worthwhile to put in a bias lighting? I'm concerned about not being able to see shadow details with smaller eye iris and unneutral reflections off my beige colored wall.

Q: If I want to measure brightness and color of the bias light, what is the correct way to do it? Should I hold the colorimeter in the air next to my plasma TV and point it towards the wall?

TIA

Q: If I don't have any eye strain issue with dark room viewing, is it still worthwhile to put in a bias lighting? I'm concerned about not being able to see shadow details with smaller eye iris and unneutral reflections off my beige colored wall.

Q: If I want to measure brightness and color of the bias light, what is the correct way to do it? Should I hold the colorimeter in the air next to my plasma TV and point it towards the wall?

TIA
Q#1: Please review the following post and draw your own conclusion: http://www.avsforum.com/avs-vb/showthread.php?t=1162578

Q#2: Yes, or use a visual comparison with the correct test pattern for ambient light level from the 'Avia' or 'Digital Video Essentials' series of optical disc programs.

Is it OK to put a piece of folded paper or something between the baffle tube and the plastic bulb fixture so as to hold the baffle tube in place?

The baffle tube is quite loose (on mine anyway) and simply turning the light on/off can affect it's position. Dusting aswell is problematic. This means I need to reset the illumination every few days.

I'd really like to just set and forget.

Thanks.

You are the first customer to have stated such a problem since we started using the baffle tubes. It would better to use something less flammable than paper. Perhaps a small piece of electrical tape?

You are the first customer to have stated such a problem since we started using the baffle tubes. It would better to use something less flammable than paper. Perhaps a small piece of electrical tape?

Thanks George, I shall try electrical tape.

Is the baffle tube supposed to be tightish by the way?

Most of them end up not being loosey-goosey, like yours seems to be, due to how close the lamp (bulb) ends up being to the fixture body. I've noticed that an occasional fixture assembly allows a bit more space under the lamp. This kind of discussion is actually getting off topic and would be best conducted via the company's e-mail.

George, has any work been done, from either a calibration standpoint, bias lighting, etc., to account for quantifiable differences in viewer eyesight?

I'm really glad that efforts have extended beyond the display device to address other factors in the signal chain that can effect how information is conveyed through the medium of television. While I believe that measured reference output from a display is a good starting point for conveying "all that which the artist intended", I also submit that the statement "only a display calibrated to the reference standards can convey to the viewer the image the artists intend" is nothing more than a conceit...I'll try to explain why I feel this is the case.

It is a well known fact that age can affect a user's eyesight. As we age, we lose the ability to distinguish levels of contrast, and our ability to gather information from the presence of certain colors at a given luminance degrades over time. It is my belief that my own vision adequately approximates an ideal from a color reproduction standpoint, to where I prefer an image calibrated approximately to the reference standard...in other words, I don't have any eyesight trouble that I know of in the waking world beyond that which is easily corrected by prescription lenses. However, this is not the case for many people: For some, a display calibrated to at or below reference black may appear overly dark, and not because of something so conveniently nebulous as user preference...rather, a viewer's ability to perceive information rising out of black may be hindered by that user's eyesight in a way that is outside that user's control or ability to alter perception.

Comments about reference displays accurately depicting the intent of the artist abound, but I hardly believe that any artist, engineer, or other person in the video production chain believes that information immediately visible to some, and representing information important to the artist, be completely lost on a certain subset of viewers. For example, I don't believe that it was James Cameron's, or any other person who worked on the movie Aliens, intent that the viewer perceive half the movie as a group of people screaming and firing weapons in a broom closet with the door closed, with only the occasional explosion or muzzle flash to let the viewer know they didn't forget to switch on their display. This is an absurd notion, yet it is the reality for some viewers of a reference display.

My question, then, becomes one of science, not of perception...in my view, the human eye is simply one more filter in the signal chain...has any work been done to provide standards for addressing differences in human visual acuity, or methods involved for assessing user eyesight in a way that is quantifiable and able to be applied to display calibration, bias lighting, etc? For example, instead of calibrating a display to a reference RGB 16 for black and 235 or above for white, is there any standard or procedure that would narrow this for a user of limited eyesight? Although said differences in vision may not be easily corrected with a simple linear factor, I would suppose that there is a method by which an adequate transform function may be arrived at for certain maladies of the eye, and accounted for on a lookup table or other similar means of tracking, similar to (but perhaps more dimensionally complex than) the way in which a viewer's ability to distinguish letters on an eye chart results in a prescription for eyewear.

The motion imaging industries rely on what are generally regarded as objective instruments, NIST trace-able for consistent accuracy, when setting up critical monitors in program mastering. Standards, engineering guidelines, and recommended practice documents guide the technicians who calibrate and use these monitors. Image performance and viewing environment conditions follow these methods. All this theory and practice is intended to unify results, independent of unique/individual human variables. Since natural reality observable around us doesn't attempt to compensate for unique perceptual differences in each viewer, each viewer must make adjustments to suit their requirements.

Video viewing environment recommended practice is our reference starting point. Each viewer may have to tweak viewing conditions slightly to suit their unique system challenges (always remember- the viewer is a legitimate component in the system). Just as there is no perfect display, there is no perfect viewer. All displays have adjustment features to compensate for non-linearities in practical use. Our challenge is to understand how to use such adjustments properly in the context of imaging industry standards and practices. The goal should always be to achieve/preserve image fidelity and artistic integrity as much as system components allow.

Understanding all of this, I don't see how a practical/reliable/affordable method would be do-able to address the issues you have presented. You are certainly free to pursue the development of such solutions. Personally, I think your inclusion of prescription eye wear may be the right remedy for the vast majority of people. What has been done for the cases you mention in the commercial cinema? How about computer monitors? Photo printers? If nothing has been done, why not?

Best regards and beautiful pictures,
G. Alan Brown, President
CinemaQuest, Inc.
A Lion AV Consultants Affiliate

"Advancing the art and science of electronic imaging"

What has been done for the cases you mention in the commercial cinema? How about computer monitors? Photo printers? If nothing has been done, why not?


Why, nothing, of course...they adhere to a reference standard because they must serve the larger audience, whose vision, on balance, probably approximates what the engineer doing the master has/had.

The difference here is that a display used in a personal environment may be set to the needs of a single individual...and indeed, may be the only place said individual has the opportunity to be imparted all the information normally visible to the majority of others watching displays calibrated to a reference standard.

I also understand that a reference display can be said to most accurately mimic reality, if said reality is recorded with a reference camera, etc., and the resultant image is measured with reference equipment. For some, that is enough. But for those experiencing loss of vision over time, television might be the only refuge they have capable of providing an approximation of the sights and sounds they became used to over most of their lives, then were deprived of.

It is analogous to my example of prescription eyewear (but the example doesn't convey all aspects): I need glasses to read. You can speak all day on the advantages of a given printing or other process of production in the conveyance of clear images...but without my glasses in the signal chain, even the Mona Lisa herself is a blurry mess, and what is reported by my eyes could not be described in any fashion as "the intent of the artist". I'm not suggesting everyone view the Mona Lisa through my glasses; I am, however, suggesting that a personal device may be constructed (prescription glasses) by which the image, though altered from the norm, conveys more accurate information from the artist to the viewer, and enables more people to enjoy the work in measurably the same way that the artist attempted. By virtue of the controls on many televisions, I submit that a television could be another such device for some people.


Now, you can argue that manufacturers/artists do not by and large make print or artwork in sizes that take into account nearsighted people, but for a visual reproduction system in my own home, where lack of other alternatives exist, I may be very right in pointing out that there is a definite desire on the part of some consumers for devices that can...indeed, in some instances, there is a need.

I'm not suggesting that manufacturers or calibrators should account for glaucoma or retinal damage in their designs for consumer-grade devices, I was just wondering if any research has been done to, say, match a reference gamma curve to an individual's eyesight in order to provide a more meaningful approximation of the intended information in transit (and indeed, for said individual, more closely resembling that which the engineers saw on their reference display)...in other words, have we gone beyond the simple brightness/contrast adjustments to account for user eyesight in a measurable and predictable way, or is it a question that has not even been posed by display science (although I doubt this is the case)?

In a general sense, I believe that the reference standards exist for a valid and true purpose...if the engineer's vision and preferences can be regarded as "accurate" (which is quite the supposition in and of itself), and the medium of transmission and measurement be agreed upon, then reference points can provide an example of a display's ability to be adjusted and adhere to certain behavior in repeatable fashion. For a viewer whose vision behaves in accordance with the production team's, these reference standards may represent the points where a display best conveys the experience the artist intended. But I think people in this forum get "reference standard" and "best" confused. There is (gasp) a sense of elitism that exists here that doesn't take into account changes in vision over time, and neglects the end user's vision as a valid and often-times predictable and measurable component to information retrieval. I submit that if any user of this forum were given back the eyesight they experienced as a child, it would come as a shock to them with regard to the values they attribute to the color red, for example, and the amount of information they received about the world through those younger eyes. Perhaps what some regard as "wrong" settings, designed to sell televisions in retail settings, or set to the desires of an individual, more closely approximate that past experience of reality for some...and indeed, from an objective standpoint, could serve to be more beneficial in terms of the amount of accurate information transmitted, for more people than would be guessed by the majority of forum members.

We would do well to remember that all these standards, the D65 gamut, standards for brightness and contrast, even the bit rate of various transmissions, are all organized within, or a subset of, a set of perceived boundaries of human senses. I believe that reference standards for display emissions exist as a starting point, and I envision (pun intended) a world where more differing aspects of the user's own senses are quantified and adjusted for, allowing us to come closer to achieving the common experience and enabling a more personal means to communicate accurate information.

For the time being, we have enough of a problem just getting our sets to behave in accordance with agreed upon, uniform standards. One might express a certain level of concern that manufacturers are pursuing 3-D and internet-enabled entertainment in an environment where they don't even have color right yet for the majority of consumers. In 2010! But my hope is that we can arrive at that point one day, and that we move on from there. Who knows? Perhaps reference quality will, for all intents and purposes, be achieved with OLED or some other technology...but my sincere hope is that we do not stop at that point.

Don't hold your breath. I think it's doubtful such solutions would be economically viable for anything other than an outboard video processor of some sort, if even that. I suggest you devote yourself to starting a new thread to promote your ideas, hopes, and dreams. This is getting way off the topic of this thread.

suggest you devote yourself to starting a new thread to promote your ideas, hopes, and dreams. This is getting way off the topic of this thread.

Agreed, it's a little OT for this thread, but thanks for your time in answering.

Well, it's not that far OT:

The world's most perfect calibration instrument cannot measure how our brain interprets what our eyes see. Some attempts have been made to emulate how humans perceive light but science has yet to produce an instrument which tells the whole story.
:)

Don't hold your breath. I think it's doubtful such solutions would be economically viable for anything other than an outboard video processor of some sort, if even that.

I dunno...ten years ago, if you'd have told me there'd be an afforable device that could fit in your ear discretely, offering a frequency response filter designed around your own hearing to return it to what you enjoyed years ago, and that said device would wirelessly connect to your telephone, stereo, or television system, I'd have thought you were talking Star Trek.

Well, it's not that far OT:
Nice try. This thread is about viewing environment conditions. Your points became focused primarily on display adjustments that could compensate for individual vision problems. That's why I suggested you start your own thread. Such a discussion may have interest and merit within this community, but the only sure way to tell is to start one in its own thread. For clarity, simplicity, and coherency, I would like this one to stay on viewing environment principles.

I have a 50G10 Panny plasma in a "theater room" with no windows and no ambient light (other than my receiver display). I'm always looking for ways to improve the perceived contrast ratio of my display and I was thinking about bias lighting as a way to improve this. However, I'm not sure that I can use bias lighting and here's why...

My display is on a stand in a wall alcove. In essence, the display is flush with the walls on either side of it but since it is in an alcove, there is about 2' of unused space behind the display. If that wasn't enough, the alcove has 2 built in shelves. One is directly behind the center of the display and the other one is directly above the top of the display. I'm assuming that if I install a bias light on the back of my set, it will do no good because the light will not reflect properly and I most definitely will not get an even amount of illumination around my set.

Can someone please chime in on this. Is it worth it to try the lighting? I do not get any eyestrain while watching the display for hours so I would be installing the lighting strictly for improved contrast ratio perception since Panasonic decided to elevate the MLL's of their displays after certain 'on' hours. If the back of my set faced a flush wall I probably would have already purchased the lighting but I don't want to get stuck with a $60 light that might not do what it was intended to do because of my wall situation.

Your assumptions are correct. Unfortunately, many display systems were originally designed without a sufficient understanding of video best practices. Many times compromises are unavoidable, so we do the best we can with the hand dealt to us. You could consider walling off the alcove, either permanently or temporarily (like with movable acoustic panels). It sounds like this is a room you have dedicated to watching movies. You get to decide what your personal lifestyle priorities are.

I have a 6500K bias light on beige colored wall. When I measure the reflected bias light with a meter, I get somewhat warmer color than the desired D65. I don't recall the exact number but I think it was between 5000K and 6000K. I guess this is expected due to the wall color. Is there a way to remove this color bias? Try using a bulb with higher temperature rating (e.g. 7000K) or add a blue filter? I suspect many people have the same issue but I couldn't find any previous discussion on this topic. TIA.

You could try using pale blue theatrical filter gells but they will only take the yellow out. There will be red content in the wall color as well, and who knows what other colors.

I was informed by one of my customers that he learned about bias lighting from this 30 minute video program: http://revision3.com/hdnation/koreatrip . The portion discussing bias lighting is from 18:53 through 23:10. It doesn't mention my company or products but is the best presentation video I've seen on the topic to date. You don't have to watch the entire video stream. Placing your mouse cursor in the video image, once the video fully loads, reveals a slider you can use to select the right time into the program.

Here's a direct link to just the bias lighting section of the video:
http://revision3.com/hdnation/koreatrip/darker-blacks-better-contrast-mod-your-hdtv-with-bias-lighting-

These videos demonstrate how even subtle changes in ambient lightness can instantly alter our black level perception of an object: http://www.youtube.com/watch?v=xl1lLze5ZpM&feature=channel ; http://www.youtube.com/watch?v=rFmgSP97fTg ; http://www.youtube.com/watch?v=kdOQBPCOk5w&NR=1 http://www.youtube.com/watch?v=MMJ6thfG2Vg&feature=channel . This explains why backing up a TV with a dark wall can be counterproductive in preserving convincing blacks on the screen. Only the darker portions of the screen image are enhanced by a lighter surround. The lighter areas of the image are not affected, therefore increasing perceived contrast ratio as well. These quotes document this characteristic:

"Contrast could be considered to be the most significant quality that impacts not only the perceived depth of an image, but also affects the apparent sharpness.....While the luminance level of a given image affects how the eye perceives contrast and detail, the ambient conditions surrounding the image can also have a dramatic impact. This phenomena was studied by Bartleson and Breneman (1967) to examine the impact of perceived contrast based not only on the luminance level of the image but taking into account the surrounding ambient luminance levels as well. Their results showed that the perceived contrast increased as ambient luminance increased. With the increase in ambient luminance, the eye interprets black levels as being darker while the impact to the white level is minimal. Since the perceived difference in dark areas is greater under the higher ambient luminance conditions, the perceived contrast is higher. It is a natural tendency to want low ambient luminance levels to strive for "better" perceived image quality and what is thought to result in higher contrast. However, in reality, the opposite is true. This tendency may be justified for current direct view CRT televisions due to the issue of glare that results from the glossy surface of the glass tube [also true for certain flat panel displays today]. With less ambient luminance, the glare is reduced- but it may be important to keep some ambient luminance behind the television [as in the case of bias lighting] to keep the perceived contrast higher.....While sharpness can affect the apparent contrast of an image, the converse is true in that contrast can also impact the apparent sharpness of an image. Images that have lower contrast will appear to be not as sharp as an image of the same content, but with higher contrast.....A subjective study was then conducted to verify the impact that ambient lighting has on perceived contrast. Several non-technical (and thus presumably non-biased) and technical observers were asked to compare a series of images with various ALL [average luminance levels] under different ambient luminance extremes in order to understand the impact that ambient viewing conditions might have on the perceived contrast between the two television technologies [CRT and DMD (DLP RPTV)]. Under dark ambient conditions, the result for images with an ALL > 5% was found to be equal between the CRT and the first DMD display. However, under bright ambient conditions (about 250 nits of luminance on the wall behind all of the units), the DMD display was favored over the CRT by 50% of the observers as having higher perceived contrast.....This proved that ambient conditions have the effect of potentially raising the black level threshold of the eye above the actual black level of the television such that the perceived contrast ratio is higher." from the SMPTE Journal, 11/02. 'The Importance of Contrast and its Effect on Image Quality' by Segler, Pettitt and Kessel

"Their experimental results, obtained through matching and scaling experiments, showed that the perceived contrast of images increased when the image surround was changed from dark to dim to light. This effect occurs because the dark surround of an image causes dark areas to appear lighter while having little effect on light areas (white areas still appear white despite changes in surround). Thus since there is more of a perceived change in the dark areas of an image than in the light areas, there is a resultant change in perceived contrast.....Often, when working at a computer workstation, users turn off the room lights in order to make the CRT display appear of higher contrast. This produces a darker surround that should perceptually lower the contrast of the display. The predictions of Bartleson and Breneman are counter to everyday experience in this situation. The reason for this is that the room lights are usually introducing a significant amount of reflection off the face of the monitor and thus reducing the physical contrast of the displayed images. If the surround of the display can be illuminated without introducing reflection off the face of the display (e.g., by placing a light source behind the monitor that illuminates the surrounding area), the perceived contrast of the display will actually be higher than when it is viewed in a completely darkened room." from 'Color Appearance Models,' by Mark D. Fairchild, Ph.D., of the Chester F. Carlson Center for Imaging Science: Munsell Color Science Laboratory

Best regards and beautiful pictures,
G. Alan Brown, President
CinemaQuest, Inc.
A Lion AV Consultants Affiliate

"Advancing the art and science of electronic imaging"

Here are a couple of pertinent excerpts from Charles Poynton's 5/26/10 article titled: 'B, V and M Are Obsolete' (http://www.spectracal.com/documents/Poynton%27s%20Vector%205.pdf)

"I use the word “reference” because the display used at the end of the
content creation chain establishes the intended reference for all downstream
displays. If an identical display is present downstream in an
identical environment, then it should present an identical picture. In
the consumers’ premises, we don’t expect the tight tolerances of
a studio display, but we do seek the same aim points."

"Color appearance is strongly influenced by surround conditions. My
recent proposal for a new standard is entitled 'studio HD reference
display and viewing conditions.'" [emphasis is mine]

Hi,

I have a question regarding how much of the space surrounding the tv should be of neutral color. Should I aim to make everything in my field of view neutral, all the way to the very limits of my peripheral vision? Or would 12 or so inches around the screen, like Ictusbrucks is planning, be sufficient?

Thanks in advance, lots of interesting info in this thread.

Hi,

I have a question regarding how much of the space surrounding the tv should be of neutral color. Should I aim to make everything in my field of view neutral, all the way to the very limits of my peripheral vision? Or would 12 or so inches around the screen, like Ictusbrucks is planning, be sufficient?

Thanks in advance, lots of interesting info in this thread.
As in life, most things in this topic are by degrees. I have encountered no definitive/authoritative statements regarding your question. It's a human condition to gravitate toward dogmatism and rigid pronouncements. The ideal is good to shoot for, just not always 100% practical in specific applications. Most important is to understand the essential principles involved and intelligently adapt to conditions in the specific system.

In other words, provide as much neutral surround as feasible. Any amount is better than nothing. Balance the priorities at issue for your circumstance. Far too many system designers don't know enough about viewing environment principles and human perceptual factors to make informed and balanced recommendations.