Do I need ALR or Grey screen? - Page 2 - AVS Forum | Home Theater Discussions And Reviews
Forum Jump: 
 19Likes
Reply
 
Thread Tools
post #31 of 49 Old 06-16-2019, 09:49 AM
AVS Forum Special Member
 
bud16415's Avatar
 
Join Date: Jan 2006
Location: Erie Pa
Posts: 7,824
Mentioned: 115 Post(s)
Tagged: 0 Thread(s)
Quoted: 2128 Post(s)
Liked: 1074
Quote:
Originally Posted by b curry View Post
Personally, I would use a white screen of ~1.0 gain for overall picture quality.

If you feel your projector is too bright for night use, you have the option of three lamp brightness settings with the HC3700; High, Medium, and ECO. Using a lower lamp setting will reduce brightness while keeping the same overall settings.

You can also use what's call an ND or Neutral density filter in front of the lens. An ND filter in front of the lens will reduce the light output while preserving color balance. ND filters are specified by their light-reducing ability in filter strength by f-stops and a wide range is available.
As an example a ND2 filter will filter out half the brightness of the projector and do the exact same thing as an ND2 screen commonly called a .5 gain neutral gray. They will both produce the exact same image in a perfect room. The exception is that in a room that is not perfect the .5 gain neutral gray screen will also remove 50% of the bad effects caused by ambient light, both light entering the room and projector light reflecting off the room.

There will be an improvement in PQ with the gray screen over the filter in all rooms as there is no such thing as a perfect room. It is more the degree of imperfect that is the factor.

Bud
bud16415 is offline  
Sponsored Links
Advertisement
 
post #32 of 49 Old 06-16-2019, 10:30 AM
AVS Forum Special Member
 
b curry's Avatar
 
Join Date: Feb 2002
Location: on the way to Hell, Michigan USA
Posts: 4,605
Mentioned: 57 Post(s)
Tagged: 0 Thread(s)
Quoted: 1034 Post(s)
Liked: 651
Quote:
Originally Posted by bud16415 View Post
As an example a ND2 filter will filter out half the brightness of the projector and do the exact same thing as an ND2 screen commonly called a .5 gain neutral gray. They will both produce the exact same image in a perfect room. The exception is that in a room that is not perfect the .5 gain neutral gray screen will also remove 50% of the bad effects caused by ambient light, both light entering the room and projector light reflecting off the room.

There will be an improvement in PQ with the gray screen over the filter in all rooms as there is no such thing as a perfect room. It is more the degree of imperfect that is the factor.
Sorry, I disagree.

A quality ND filter will reduce the light output without affecting color.

The same cannot be said of the gray screens and there are variances in the effect depending on the gray screen material/color. Any white light area on a gray or so called dark screen will also be gray and measure so.

I'm not in any way saying that there is not a place for gray screens or ALR screens. What I did say was that for best PQ with regards to color accuracy a good quality white screen will produce the best results.

Anecdotally, I've compared/measured full sized Stewert Filmscreen FireHawk and Studiotek screens.

Anyone trying to bridge high ambient light environments with light controlled/lights off viewing is settling for a compromise one way or the other with regards to screen material. Early digital projection projectors and today's lower cost units can benefit from gray screens for improved/enhanced black levels in non-optimum viewing environments and off-axis viewing.

Quality, matte white screens present the strictest color and white field uniformity to the viewer. Gray screens strive to meet that goal in no-optimum rooms or equipment. You won't find a gray screen in a SOTA home theater or commercial color grading screening room.
b curry is online now  
post #33 of 49 Old 06-16-2019, 11:49 AM
AVS Forum Special Member
 
bud16415's Avatar
 
Join Date: Jan 2006
Location: Erie Pa
Posts: 7,824
Mentioned: 115 Post(s)
Tagged: 0 Thread(s)
Quoted: 2128 Post(s)
Liked: 1074
Quote:
Originally Posted by b curry View Post
Sorry, I disagree.

A quality ND filter will reduce the light output without affecting color.

The same cannot be said of the gray screens and there are variances in the effect depending on the gray screen material/color. Any white light area on a gray or so called dark screen will also be gray and measure so.
Any true neutral density gray will reduce light output without affecting color also.

It is a commonly misbelieved that a gray screen will produce a white that is gray in color. Neutral gray is composed identically to white in color as it is white with the intensity turned down. Just the same as a ND filter blocks some of the light and lets some pass unchanged a ND screen absorbs some of the light and reflects some unchanged.

The way I like to describe an ND screen is picture a football covered in a checkerboard pattern of 1” squares alternating white and black. Up close we see white and we see black now move up 1000’ and view the field it will look like it is a 50% gray. The white squares are still reflecting 100% just as a white screen will, the black squares are hopefully absorbing 100% or reflecting zero %. Nothing has changed in the color spectrum and if twice the light strikes the combined surface it will look the same as if it is white. What does a white screen look like in a totally black theater with the projector off? It looks black.

It is a misconception a gray screen can not project white. Here is a screen shot off my .5 gain ND gray screen. If it did not produce the full spectrum and trimmed the spectrum of white I would never watch it.
Attached Thumbnails
Click image for larger version

Name:	IMG-8676.jpg
Views:	74
Size:	849.8 KB
ID:	2580772  
Don Stewart likes this.

Bud
bud16415 is offline  
Sponsored Links
Advertisement
 
post #34 of 49 Old 06-16-2019, 12:56 PM
AVS Forum Special Member
 
Dave in Green's Avatar
 
Join Date: Jan 2014
Location: USA
Posts: 8,354
Mentioned: 152 Post(s)
Tagged: 0 Thread(s)
Quoted: 3787 Post(s)
Liked: 3001
By definition neither a true neutral grey screen nor a true neutral density filter will affect color because they are both color neutral. The issue is that true neutral density filters are easy to come by and relatively inexpensive. True neutral grey screens are hard to come by and relatively expensive. The inexpensive grey screens on the market are not color neutral and typically produce varying degrees of color shift that require recalibrating the projector, and proper calibration requires specialized test equipment.

@Cla55clown , when you test your white outdoor screen in the basement with lights on be sure to experiment with different lighting. For example, if you have any lights that shine directly on the screen try unscrewing those bulbs if they aren't on a separate circuit so that the area of the basement where the screen is placed is in the shadows. Best practice for viewing video projection with lights on is to properly manage the lighting so minimal light falls near the screen area.

As for ALR screens they each have a different set of pros and cons. While some are enthusiastic about them others are put off by some of the cons such as reduced viewing cone and visual artifacts. ALR screens with minimal issues are typically significantly more expensive than matte white (or matte grey) screens. Properly managing ambient light so it has minimal impact on a matte white screen can be very effective and is easily the least expensive solution with the least negative side effects.
Cla55clown likes this.
Dave in Green is offline  
post #35 of 49 Old 06-16-2019, 01:58 PM
Advanced Member
 
Don Stewart's Avatar
 
Join Date: Sep 2000
Location: Stewart Filmscreen Corporation. USA
Posts: 620
Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 174 Post(s)
Liked: 194
Quote:
Originally Posted by bud16415 View Post
Any true neutral density gray will reduce light output without affecting color also.

It is a commonly misbelieved that a gray screen will produce a white that is gray in color. Neutral gray is composed identically to white in color as it is white with the intensity turned down. Just the same as a ND filter blocks some of the light and lets some pass unchanged a ND screen absorbs some of the light and reflects some unchanged.

The way I like to describe an ND screen is picture a football covered in a checkerboard pattern of 1” squares alternating white and black. Up close we see white and we see black now move up 1000’ and view the field it will look like it is a 50% gray. The white squares are still reflecting 100% just as a white screen will, the black squares are hopefully absorbing 100% or reflecting zero %. Nothing has changed in the color spectrum and if twice the light strikes the combined surface it will look the same as if it is white. What does a white screen look like in a totally black theater with the projector off? It looks black.

It is a misconception a gray screen can not project white. Here is a screen shot off my .5 gain ND gray screen. If it did not produce the full spectrum and trimmed the spectrum of white I would never watch it.
Bud is dead on correct with his comments above. A true ND Gray will not effect image color as black, white and shades of gray are not technically classified as colors such as red, green and blue, etc. Here is were the human factors kick in. When our eye/brain processes a projected image when viewing on a ND gray screen, the brightest" Luminance", (100% IRE from the projector of white light) will become our brain's benchmark for a pure white. When viewing lower luminance of white light, our brain will interpreter them as shades of gray when compared to the brightest white available. The photo demonstrates white light on a studio reference white screen and on a very dark gray ALR screen with true neutral density. Both the white screen and the ND ALR screen have the exact amount of foot lamberts of white light returning to the viewer. As one can see, the white light on the ND gray screen is just as pure as the white reference screen.
Attached Thumbnails
Click image for larger version

Name:	StudioTek 100-Phantom HALR Split Screen, Tower Bridge Zoomed in.jpg
Views:	81
Size:	96.8 KB
ID:	2580810  

Manufactures of Precision Professional Projection Screens.
An ISO 9001:2015 Certified Company.
UL GREENGUARD Certified For Environmentally Friendly Products.
http://www.stewartfilmscreen.com/

Last edited by Don Stewart; 06-16-2019 at 02:11 PM.
Don Stewart is offline  
post #36 of 49 Old 06-17-2019, 05:52 AM
AVS Forum Special Member
 
bud16415's Avatar
 
Join Date: Jan 2006
Location: Erie Pa
Posts: 7,824
Mentioned: 115 Post(s)
Tagged: 0 Thread(s)
Quoted: 2128 Post(s)
Liked: 1074
Quote:
Originally Posted by Don Stewart View Post
Bud is dead on correct with his comments above.
Thanks Don for chiming in and the great illustration.
Many are confused as @b curry is about true ND gray screens and as @Dave in Green mentioned there are so few out there to pick from. People associate all dark screens together and when a dark screen is represented as even 1.0 gain they assume it has lambertine light reflecting properties. Where in fact to get the 1.0 gain rating it likely has the viewing cone cut in half. This type of screen in terms of color neutrality at that point is totally up to the skills and process the screen maker uses to achieve the actual high gain to overpower the dark pigment. For that reason people should be aware of both the advertised gain and the half gain angle of a screen as that tells the whole story.

I had high hopes of a resurgences of ND gray screens as digital projectors continued to get brighter and still maintain higher CR numbers over the last few years. Then came along 4k with this desire for projectors to also do HDR duty like a TV screen with bright highlights and not being able to reach TV lumen levels options for some brightness and combined tone mapping is where all the talk is now for achieving HDR-like images.

As you mentioned the human factor is always going to kick in as our vision limits brightness it allows in. Projection is intended for dark colored light absorbing rooms with little to no light in the room other than the projector. The industry is trying to make projection into something else and it is somewhat successful with the latest batch of projectors and screens. If flat panel TVs didn’t keep raising their game with size and quality it wouldn’t have been to hard for projection to pull ahead, but as it is the only real advantage projection will have is screen size unless we level the playing field and go back to where projectors work their best and that is in a dark environment.

For me that black environment without distractions and allowing the “Human Factor” to fully kick in is what I want. The ND gray screen has allowed me to have that in the dark and then in the next moment switch the projector to be brighter and get a little of the ambient room ability also. It was working pretty good, but if I start wishing for HDR in my images I’m not sure there are projectors ready for that task and a ND gray screen at the same time. At least not any I can afford.
NxNW likes this.

Bud
bud16415 is offline  
post #37 of 49 Old 06-17-2019, 07:31 AM
AVS Forum Special Member
 
b curry's Avatar
 
Join Date: Feb 2002
Location: on the way to Hell, Michigan USA
Posts: 4,605
Mentioned: 57 Post(s)
Tagged: 0 Thread(s)
Quoted: 1034 Post(s)
Liked: 651
Quote:
Originally Posted by Don Stewart View Post
Bud is dead on correct with his comments above. A true ND Gray will not effect image color as black, white and shades of gray are not technically classified as colors such as red, green and blue, etc. Here is were the human factors kick in. When our eye/brain processes a projected image when viewing on a ND gray screen, the brightest" Luminance", (100% IRE from the projector of white light) will become our brain's benchmark for a pure white. When viewing lower luminance of white light, our brain will interpreter them as shades of gray when compared to the brightest white available. The photo demonstrates white light on a studio reference white screen and on a very dark gray ALR screen with true neutral density. Both the white screen and the ND ALR screen have the exact amount of foot lamberts of white light returning to the viewer. As one can see, the white light on the ND gray screen is just as pure as the white reference screen.
So you're saying that the white balance and black body emissivity is identical for both screens discounting Luminance?
b curry is online now  
post #38 of 49 Old 06-18-2019, 04:36 AM
AVS Forum Special Member
 
bud16415's Avatar
 
Join Date: Jan 2006
Location: Erie Pa
Posts: 7,824
Mentioned: 115 Post(s)
Tagged: 0 Thread(s)
Quoted: 2128 Post(s)
Liked: 1074
Quote:
Originally Posted by b curry View Post
So you're saying that the white balance and black body emissivity is identical for both screens discounting Luminance?
I don’t want to put words in Don’s mouth but I thought his reply you quoted explained it quite well, and the photo gave a reference point for understanding.

Bud
bud16415 is offline  
post #39 of 49 Old 06-18-2019, 08:37 AM
AVS Forum Special Member
 
b curry's Avatar
 
Join Date: Feb 2002
Location: on the way to Hell, Michigan USA
Posts: 4,605
Mentioned: 57 Post(s)
Tagged: 0 Thread(s)
Quoted: 1034 Post(s)
Liked: 651
Quote:
Originally Posted by bud16415 View Post
I don’t want to put words in Don’s mouth but I thought his reply you quoted explained it quite well, and the photo gave a reference point for understanding.
Thanks, but I'm patiently waiting for the answer. The photo doesn't address or answer my question with regards to black-body or white balance. Perhaps you're confused?
b curry is online now  
post #40 of 49 Old 06-18-2019, 02:17 PM
AVS Forum Special Member
 
bud16415's Avatar
 
Join Date: Jan 2006
Location: Erie Pa
Posts: 7,824
Mentioned: 115 Post(s)
Tagged: 0 Thread(s)
Quoted: 2128 Post(s)
Liked: 1074
Quote:
Originally Posted by b curry View Post
Thanks, but I'm patiently waiting for the answer. The photo doesn't address or answer my question with regards to black-body or white balance. Perhaps you're confused?
I am confused, but that doesn’t take too much these days.

The statement you made that I questioned you said “Sorry, I disagree.

A quality ND filter will reduce the light output without affecting color.

The same cannot be said of the gray screens and there are variances in the effect depending on the gray screen material/color. Any white light area on a gray or so called dark screen will also be gray and measure so. “. I said an ND gray screen will act exactly the same as the ND filter in a perfect room and will give improved performance in a less than perfect room. Don as far as I read agreed with my statement. In Don’s photo example both surfaces were setup to have the same returning FL and show white as white within the same image.

I will attach an image made years ago when the DIY screen alchemists were concocting paint formulas to cover the whole range of ND gray paints to match up to Munsell grays 0-10. These two photos depict a M10 white against an M7 or 8 gray under the same amount of illumination. So the gray sample is at a disadvantage by a small amount. The samples are white on the left and ND gray on the right. The one photo was taken in total darkness while the other had some ambient room lights turned on.

In my case I’m using a M5 screen surface (50% gray/.5 gain) and have adjusted my lumens upward to compensate. My theater can be made to be absolutely dark with zero light admittance and in terms of room reflectance my guess is I’m as good if not better than most commercial theaters and 75% of the way to perfect. So my lights out movie watching is IMO the same as if I had a unity gain white screen using half the lumens or employing a ND2 filter. Where I see big improvements is when I use my theater room to host sporting events or for social TV viewing where we don’t want all the lights out. There is improvement even without bumping the brightness under these circumstances and even greater improvement on some content with bumping the brightness.

The reason you won’t find these screens in “ a SOTA home theater or commercial color grading screening room” is because they are perfect rooms and there is no desire for turning lights on. Of course in such a setting 1.0 unity white can’t be beat. It could be tied but what would be the point in wasting illumination.
Attached Thumbnails
Click image for larger version

Name:	IMG_2257.jpg
Views:	63
Size:	236.7 KB
ID:	2581726   Click image for larger version

Name:	IMG_2256.jpg
Views:	62
Size:	246.1 KB
ID:	2581728  

Bud
bud16415 is offline  
post #41 of 49 Old 06-18-2019, 02:43 PM
Member
 
Malodium's Avatar
 
Join Date: Nov 2009
Location: USA
Posts: 88
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 49 Post(s)
Liked: 12
Bud, could you tell us what screen you are using? Is it a commercial screen or did you make it? I am in the same situation as the OP here and need to figure out what screen will work best in my non-optimal basement setting. I had been planning on trying Carl's grey material.
Thanks for all the info!


Edit:re-reading your last post it looks like you are using some grey paint?

Last edited by Malodium; 06-18-2019 at 02:51 PM.
Malodium is offline  
post #42 of 49 Old 06-18-2019, 02:56 PM
AVS Forum Special Member
 
bud16415's Avatar
 
Join Date: Jan 2006
Location: Erie Pa
Posts: 7,824
Mentioned: 115 Post(s)
Tagged: 0 Thread(s)
Quoted: 2128 Post(s)
Liked: 1074
Quote:
Originally Posted by Malodium View Post
Bud, could you tell us what screen you are using? Is it a commercial screen or did you make it? I am in the same situation as the OP here and need to figure out what screen will work best in my non-optimal basement setting. I had been planning on trying Carl's grey material.
Thanks for all the info!


Edit:re-reading your last post it looks like you are using some grey paint?
My DIY screen is a stealth screen wall. No given size no given AR. I’m running the last/old generation 1080p DLP projector with dark chip 3 technology. With the dark gray screen and a smaller screen size 110” max I do fine with no masking. My seating distance is 8’ so the 110” is my IMAX size and I zoom down for other movie types where I want less immersion. Keeping the screen size down allows me with a regular projector to have the lumens needed to go as gray as I have.

I would conceder a commercial screen but the choices that dark in a true ND gray are very limited. It is also not to hard to paint a ND gray screen if you have a good flat wall to start with. Mine is a drywall wall I built and took care to keep it very flat and smooth.

There is a DIY screen forum here it is a sub forum of this one.

Bud
bud16415 is offline  
post #43 of 49 Old 06-18-2019, 06:03 PM
AVS Forum Special Member
 
Dave in Green's Avatar
 
Join Date: Jan 2014
Location: USA
Posts: 8,354
Mentioned: 152 Post(s)
Tagged: 0 Thread(s)
Quoted: 3787 Post(s)
Liked: 3001
@bud16415 , I think @b curry is asking a specific technical question for more detailed data on white balance and black body emissivity that goes beyond the general description provided by @Don Stewart and your general follow-up. Whether or not there is any measurable difference in these specific values it would only matter to most if there was a negative effect perceived when viewing the final image.
Dave in Green is offline  
post #44 of 49 Old 06-19-2019, 04:39 AM
AVS Forum Special Member
 
bud16415's Avatar
 
Join Date: Jan 2006
Location: Erie Pa
Posts: 7,824
Mentioned: 115 Post(s)
Tagged: 0 Thread(s)
Quoted: 2128 Post(s)
Liked: 1074
Quote:
Originally Posted by Dave in Green View Post
@bud16415 , I think @b curry is asking a specific technical question for more detailed data on white balance and black body emissivity that goes beyond the general description provided by @Don Stewart and your general follow-up. Whether or not there is any measurable difference in these specific values it would only matter to most if there was a negative effect perceived when viewing the final image.
I guess I will be eagerly awaiting an answer along with everyone else.

My guess is of course the white balance will remain the same that was stated a couple times now and to black body emissivity it can not possibly be identical as additional luminance energy is required to achieve the same returning output from the screen. Light is energy and has to go someplace be it a filter or a screen.

Bud
bud16415 is offline  
post #45 of 49 Old 06-21-2019, 01:08 PM
Advanced Member
 
Don Stewart's Avatar
 
Join Date: Sep 2000
Location: Stewart Filmscreen Corporation. USA
Posts: 620
Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 174 Post(s)
Liked: 194
Quote:
Originally Posted by b curry View Post
Thanks, but I'm patiently waiting for the answer. The photo doesn't address or answer my question with regards to black-body or white balance. Perhaps you're confused?
Thank you for your patience as I do not have the time to make daily post here on AVS. The single purpose of my contribution to this thread was to validate Bud's comments in his post. It was not intended to go any deeper than that.

During my 18 and a half years of being a member of this forum, I can't tell you how many times I have read where posters say it is impossible to get a true white on a gray screen surface which is untrue. Over the years, my coworkers and myself at Stewart have had the honor and pleasure of working with and developing very specialized front and rear projection optical coatings for extremely sophisticated customers from the DOD, the US military to the very creative people out at Disney Imagineering to name a few. (Disney uses GrayMatte 0.4 and 0.7 gain screens in all their 360 Circle Vision theaters in their world wide theme parks which we developed together as a team.) Quite frankly, never during any R&D meetings with these clients did the term, "Black Body Emissivity" ever come up. That being said, when developing new products and also during the daily manufacturing of our films, we do measure and monitor for true color values. When manufacturing gray based front and rear projection films we also monitor and measure the material for a true Neutral Density gray base so that the image whites and colors are not skewed in anyway. Please note that this is deepest I want to go on a public forum. Thank you.



Best Regards,
Don
bud16415, NxNW and Cla55clown like this.

Manufactures of Precision Professional Projection Screens.
An ISO 9001:2015 Certified Company.
UL GREENGUARD Certified For Environmentally Friendly Products.
http://www.stewartfilmscreen.com/
Don Stewart is offline  
post #46 of 49 Old 06-21-2019, 03:01 PM
AVS Forum Special Member
 
Dave in Green's Avatar
 
Join Date: Jan 2014
Location: USA
Posts: 8,354
Mentioned: 152 Post(s)
Tagged: 0 Thread(s)
Quoted: 3787 Post(s)
Liked: 3001
If the term black body emissivity never once came up in any R&D meeting at Stewart Filmscreen then I guess it's up to @b curry to explain why he thinks this measure is relevant to the discussion beyond the basic concept of neutral density.
bud16415 likes this.
Dave in Green is offline  
post #47 of 49 Old 06-24-2019, 05:46 AM
AVS Forum Special Member
 
bud16415's Avatar
 
Join Date: Jan 2006
Location: Erie Pa
Posts: 7,824
Mentioned: 115 Post(s)
Tagged: 0 Thread(s)
Quoted: 2128 Post(s)
Liked: 1074
Quote:
Originally Posted by Dave in Green View Post
If the term black body emissivity never once came up in any R&D meeting at Stewart Filmscreen then I guess it's up to @b curry to explain why he thinks this measure is relevant to the discussion beyond the basic concept of neutral density.
We always talk about lumen output and making light to achieve a level of PQ we deem acceptable. We hardly ever talk about stopping the light we pay so much to make in the first place. A projector be it film or DLP or LCD or any of the conventional methods is more about blocking or stopping light than it is making it. Film and filters don’t make blue light as an example they filter out red and green and everything that is not blue. All this light has to go someplace and it is converted to heat. When a DLP deflects light away from the optics to make darker colors likewise all these lumens are wasted and converted to heat. Then there are iris projectors that throttle light output. Not to mention the waste heat that is a product of creating such a bright light source to start with. The business of projection is not a very efficient business to start with.

For that reason it was never particularly bothersome to me to waste more energy with things like an ND filter or it’s counterpart a ND screen when trying to improve or rather preserve PQ in a less than perfects setting. After all the best black you will ever get off a screen is how the screen looks in reference to how your eyes are adjusted to the ambient light level in the room. Pushing the black floor down with a darker screen and then maintaining the top end whites with more lumens wont change the projectors CR but light bouncing around in the room is going to be attenuated some by the darker screen surface.

This ability of a surface to absorb/radiate all light energy is its black body quality the emissivity is how well it does that. At least to my way of thinking. I think @b curry comments have some meaning to the discussion, but like you I’m not sure where he is going with it in terms of neutrality effecting the reflection of full spectrum visible light. I do know almost all if not all projectors do their best color reproduction and maybe CR at the conservative end of their lumen producing. Therefore in many cases that is a plus for a less attenuating white screen. It even seems to be a greater pro/con with 4k projectors trying to eke out some HDR brightness.

Maybe he will fill us in on his thoughts.
Dave in Green likes this.

Bud
bud16415 is offline  
post #48 of 49 Old 06-24-2019, 07:54 AM
AVS Forum Special Member
 
Dave in Green's Avatar
 
Join Date: Jan 2014
Location: USA
Posts: 8,354
Mentioned: 152 Post(s)
Tagged: 0 Thread(s)
Quoted: 3787 Post(s)
Liked: 3001
I really do enjoy the technical discussions on AVS Forum because I've always been casually interested in technical things even though I never worked in a technical profession. But the ultimate point I always come back to in all of these video discussions is whether or not the image looks better regardless of how it may measure in some technical area. If improving one area results in the perception of a more pleasing image despite throwing off another measure then I consider it a net gain. Of course this enters the realm of personal preference which varies from individual to individual. I'm not sure how black body emissivity and white balance discounting luminance fits into that comparison of two apparently identical images on neutral density white and grey screens, but maybe someone with good technical knowledge will drop in and explain it in layman's terms.
Dave in Green is offline  
post #49 of 49 Old 06-24-2019, 01:59 PM
AVS Forum Special Member
 
bud16415's Avatar
 
Join Date: Jan 2006
Location: Erie Pa
Posts: 7,824
Mentioned: 115 Post(s)
Tagged: 0 Thread(s)
Quoted: 2128 Post(s)
Liked: 1074
Quote:
Originally Posted by Dave in Green View Post
I really do enjoy the technical discussions on AVS Forum because I've always been casually interested in technical things even though I never worked in a technical profession. But the ultimate point I always come back to in all of these video discussions is whether or not the image looks better regardless of how it may measure in some technical area. If improving one area results in the perception of a more pleasing image despite throwing off another measure then I consider it a net gain. Of course this enters the realm of personal preference which varies from individual to individual. I'm not sure how black body emissivity and white balance discounting luminance fits into that comparison of two apparently identical images on neutral density white and grey screens, but maybe someone with good technical knowledge will drop in and explain it in layman's terms.
I agree Dave and as you know I have a DIY ND Gray screen made from regular old interior wall paints and some clear interior poly mixed together and rolled on. There is science behind the mixture what mixture I used I left 100% up to what projector / screen size combination and what my individual preference liked best. After all the end result should always be an image you like best.

So in my case I blended quite a few samples and my normal routine on a gray screen is to start slightly lighter than I think I want and then proceeded darker. One thing about a DIY screen there is a temptation to go darker with a new projector and within the first 6 months you get some lamp dimming and you find yourself literally painted into a corner. For that reason I leave extra brightness for adjusting up for when the time comes. I also run a brighter mode for 3D and I often switch between eco and normal depending if I have the room lights up.

Projection is also a lot about making compromises. People expecting any screen to alleviate all their problems in a bad room need to know that won’t happen.
Dave in Green likes this.

Bud
bud16415 is offline  
Sponsored Links
Advertisement
 
Reply Screens

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off