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White vs Gray Refresher

post #1 of 41
Thread Starter 
Here is a simple demonstration of what the difference is between a white screen and a gray screen.

In these two photos there is a matte white panel on the left side, and a matte gray panel on the right. In the first photo all lights were turned off. In the second photo I had some lights on in the room. Note that when the lights are all off the gray is almost the same as the white, however, when you have some ambient light the gray is much better than the white.





With today's brighter high contrast projectors, the use of a gray screen has more to do with ambient light tolerance. If there is any unwanted light falling on the screen, it will reveal the shade of the screen. It is most apparent in areas of the image that are dark.
post #2 of 41
Now THAT is a very good way to show the differences, in a no-nonsense way.
Well Done t .

It is CLEAR to me that the whites are suffering on that plain gray screen, although AL performance is much better.

As you may or may not know, I painted my Flat white wall a "Gray" color, it was "Pebble Beach" by Ben Moore, it was their closest match to SW7071, AKA Sherwin Williams "Gray Screen".
I also put on 2 coats of #780 Poly.

I have noticed that AL performance is much better, thats without a doubt,colors seem VG as well, but I think the whites have suffered a bit, not a HUGE amount, but they are NOT as white as they should be.

I did NOT use any metallic paints, because spraying in this small area(1 small window, with lots of stuff in here) would be a nightmare, and it seems that most folks are having issues rolling metallics.
I believe I could do it, because I've done alot of painting, but it seems the % of happy rollers using Metallics, is pretty low.

I was hoping to be all set with this by now, so I could get my room cleaned up, but alas, I am not sure I am done yet.

Does the Gray screen I painted do what it's supposed to?
Yes
Am I 100% happy with it?
Not yet
post #3 of 41
Nope, I just bought a Qt of that PB.
The screen actually looks pretty darn good, I'm used to watching a CRT RPTV, so whites and blacks were always VVG.

I watched some stuff tonight, and took a bunch of shots that I am going to look over.

I can get just about any paint I want to within 20 mins. of my house(LOTS of HW/paint stores), so if I decide to take it further, I'll have NP doing that.

TBO the PQ is VG, I'm probably just nitpicking, but thats one of the hazards of being a tweaker!!

Yeah, I have Flat white- the Ben Moore flat(ceiling) I initially had for my screen.
post #4 of 41
Yeah, I do. I also have Avia and DVE(which is a PITA).
I thought I did that already, but I'll check tommorrow evening when I get home from work. I may have made a few small ADJ. since then.
EDIT: The pic below looks like I may have turned up the contrast a bit for some reason.
Heres a pic I took tonight, black on white:
EDIT: I moved alot of pics at the host(trying to condense), so I broke the link- here it is:

post #5 of 41
Muzz

If I were you I would enjoy that DIY painted wall/ screen for a good long while before considering changing anything. If that screen shot is representative of what you are seeing lights out you are getting 99% of the contrast information IMO. I just played around with my color picker tool and your screen shot and you have blacks in that photo that registered down around RGB 9 9 9 and whites up around 250 250 250 . I suspect you are tolerating a good amount of ambient after looking at the pebble beach gray the other day. And your projector seems to have more than enough power for your setup.

I really think you are a good example of the guy I talk about that isn't going to get any significant improvements by going more complex or going into a commercial screen.

Looks really nice. How does it do with some mild lighting on?
post #6 of 41
It should also be noted that everyone isn't going to get the results Tiddler and Muzz did with these gray surfaces.

I have been a proponent of making a screen using the gray and poly method for quite some time to gain contrast improvements with and without external ambient light being a factor. But the concept of doing this works by the screen absorbing some of the projected light along with some of the ambient and even in total light control there is always going to be ambient from the projected light bouncing around the room.

This system is a compromise increased perceived contrast at the cost of loosing some brightness. Using the poly with the flat gray paint can improve the surface sheen to the screen and add a bit of gain getting back some of the losses. But you need a screen size and a projector combination that gives enough foot lamberts to pull it off.

That's why my approach and Tiddlers both follow an incremental gray scale. Its not that more gray might not be better it's a case of not going past what your projector can handle.

I would also caution people with new projectors that there will be a lessening of brightness as their projector bulb ages. Start this process with that in mind and make sure you leave yourself room in the calibration settings to add some brightness back in. A good way to do that is by setting up in econo mode to start and also brightness boost set to moderate amounts.
post #7 of 41
Tiddler, thanks for the refresher. I read it once or twice in its original location, but for some reason it 'soaked in' a little better this time. I think 'm finally starting to understand gain & reflectivity a little bit.

Can you clarify a couple of things? First, with the gray screen, which type of reflectivity is provided by the poly coat - retro or angular? Also, how about the silver component, is that different in this regard? Or is it more complicated than this?

I'm guessing the poly is angular and the silver is retro, but I dunno for sure.

Thanks for all your effort here.

- Jim the Noob
post #8 of 41
Yeah Bud, you may be right, I looked over a bunch of screenies I took last night, and alot of them look really good, like I said, I was probably just nitpicking it to death.
I took a bunch of screenies over the last week to adjust the Manual settings on the camera(Canon A85), it shows a pretty reasonable facsimile of what I'm seeing, at least according to my monitor.

AL performance is not a real big deal, because most of my viewing is in the dark, but I can have a fair amount of light on now without issue(you could read a book NP), obviously the image suffers a bit, but it can be watched NP at all, where as before I painted it gray, it washed out pretty quickly.

I'll take a few shots today with 60-135w of light, I may even dig up Black Hawk Down again, and reshoot the pics I took before, in the exact location and AL settings(all on).
post #9 of 41
Quote:
Originally Posted by muzz View Post

Yeah Bud, you may be right, I looked over a bunch of screenies I took last night, and alot of them look really good, like I said, I was probably just nitpicking it to death.
I took a bunch of screenies over the last week to adjust the Manual settings on the camera(Canon A85), it shows a pretty reasonable facsimile of what I'm seeing, at least according to my monitor.

AL performance is not a real big deal, because most of my viewing is in the dark, but I can have a fair amount of light on now without issue(you could read a book NP), obviously the image suffers a bit, but it can be watched NP at all, where as before I painted it gray, it washed out pretty quickly.

I'll take a few shots today with 60-135w of light, I may even dig up Black Hawk Down again, and reshoot the pics I took before, in the exact location and AL settings(all on).

Would be great. I think you are actually in the range of ambient light performance that I'm seeing also with your Sharp by the sound of it. And if I take the ft lamberts you are seeing based on a 16:9 projector and diminish my lumens while in 16:9 I'm willing to guess we are pretty close in Ft lamberts.

Your input is invaluable IMO to others now that this projector is taking off.
post #10 of 41
I'm sorry if this thread is getting derailed, I put those shots in my original thread.

As stated t, I really think this "refresher" of yours is a great, and SIMPLE thing for folks to see the differences afforded QUICKLY.

Thanks

m
post #11 of 41
TBO t, I think this thread should be stickied for the simple reason of EASY COMPARISON of Plain Flat White, and gray/poly, and Mettallics.

I looked around to see EXACTLY what you showed, and I have seen folks ask for that EXACT thing you showed, and most times they either aren't shown right away, or not all all.....
I wouldn't care if everything after your screenshots was deleted, and just stuck.
Believe me, this thread is INVALUABLE to folks looking for this EXACT showing, I looked ALOT when I was thinking of changing, and didn't find a better comparison, in a smaller area of looking, anywhere.

Delete EVERYTHING after the screenies/explanations and stick this, folks WILL appreciate it!!

Maybe change the name of the Thread to: Flat white vs Gray,vs Metallic Painted screen samples-Picture gallery.

That way it's a very simple thing to find, but either way it would be fine.

Well done.
post #12 of 41
Quote:
Originally Posted by tiddler View Post

...Retro-reflective requires glass beads or right angle reflective texture like a bicycle reflector. It is possible that some of the tiny mica flakes in a metallic paint surface are oriented such that they reflect the light back in the general direction of the projector but then so does a flat latex paint surface.

OK, thanks for clearing that up. Apparently the reflective particles need to be both more substantial & more specifically oriented than any of the paint solutions we're discussing here, in order to get retro-reflectivity. I'll eventually be ceiling-mounting a DLP (lotsa offset) machine. As I understand it, retro is not a quality I need or want in this case, so it's good to know I won't be "achieving" it inadvertently with any simple paint job.

By the way, I also had a follow-up or two regarding gain & viewing angle vs. different mixes, but I went back & re-examined your original presentation, and that pretty much answered those questions. I've been a little overwhelmed with all these screen decisions, but it's finally starting to get easier as I understand it more. Thanks again for your help.

- Jim the Noob
post #13 of 41
Quote:
Originally Posted by bud16415 View Post

Would be great. I think you are actually in the range of ambient light performance that I'm seeing also with your Sharp by the sound of it. And if I take the ft lamberts you are seeing based on a 16:9 projector and diminish my lumens while in 16:9 I'm willing to guess we are pretty close in Ft lamberts.

Your input is invaluable IMO to others now that this projector is taking off.

Hey, I like to help, like everyone else here.
If anything I post helps even 1 person, it was worth posting IMO.

BTW Bud, as you are aware, the Sharps are reasonably bright(NOT Infocus IN76 bright though, that must be blinding), that shot is in ECO mode (actually ALL of my pics are), and High Contrast(NOT High Brightness or High Lamp for those unaware).

PJC states 11 FL for that size/throw(accurate? I think NOT), and states Needs more brightness...... ya, sure it does.....

There's headroom for declining bulb here, which is good
post #14 of 41
Thread Starter 
Bump
post #15 of 41
Thread Starter 
Time for an yearly bump!

One thing many people don't do when going gray or trying a gray sample panel, is perform the necessary contrast & brightness calibration. In the photos above the projector was not calibrated. I too found the whites a bit dull until I did the calibration. Calibrating the contrast & brightness was the single thing that made the greatest improvement in my image quality.
post #16 of 41
Where is the best place and most recommended calibration software for the DIY besides the THX optimizer?
Probably wrong forum for that question, but goes with your post.
post #17 of 41
DIY Video Calibration: AVS HD 709:
http://www.avsforum.com/avs-vb/showthread.php?t=948496

Also, it may seem obvious but perhaps it's good to define ambient light. While I was able to 100% control outside sunlight and indoor lights, I still have a lot of light bouncing off the screen and projector and then bouncing off the walls, especially the white ceiling. When people talk about ambient light, I never thought to include a white ceiling as being part of the ambient light. Would you agree with this definition?
post #18 of 41
Thread Starter 
Quote:
Originally Posted by Pyro2 View Post

DIY Video Calibration: AVS HD 709:
http://www.avsforum.com/avs-vb/showthread.php?t=948496

Also, it may seem obvious but perhaps it's good to define ambient light. While I was able to 100% control outside sunlight and indoor lights, I still have a lot of light bouncing off the screen and projector and then bouncing off the walls, especially the white ceiling. When people talk about ambient light, I never thought to include a white ceiling as being part of the ambient light. Would you agree with this definition?

Typically ambient would imply something already available in the room. So I don't know that we are technically correct in referring to light from the screen bouncing off the ceiling and walls as ambient light, but it has the same effect of washing out the image. I like to refer to it as Rebound Ambient light. The ill effects of Rebound Ambient light are worst when the image contains both bright and dark areas. A hockey game where you have an image of bright white ice is a classic example. Typically the hockey pants the players are wearing are black. All that white light from the ice lights up a white ceiling and that in return illuminates the entire screen. The result is the black hockey pants and dark colored jerseys get washed out.

If we consider any light hitting the screen that is not being projected to create the image as "Ambient Light" then there are three main sources. These sources are as Pyro2 pointed out, sunlight through windows, lighting within the room, and light from the screen that reflects off of room surfaces and back onto the screen. For each of these sources there is an obvious way to eliminate or minimize it. For sunlight, cover the windows with light blocking blinds or drapes. For room lighting you can dim the lights but also take steps to prevent the room lighting from illuminating the screen. The most typical way to do that is to install deep can lights directly over the seating area and put them on a dimmer. To minimize or eliminate rebound ambient light you would have to paint the walls and ceiling very dark colors. Ideally you would paint all surfaces flat black, install black carpeting, and buy furniture that is upholstered in dark colored fabric.

From the very beginning my goal was to determine if it was possible to integrate front projection into a typical family or living room. To me that is what "Home Theater" really implies. A room dedicated to front projection, is really a private theater within someone's home. Typically painting the ceiling and walls black is not an option in a living room. Panasonic, Epson, and Optoma all seem to have recognized that there is a greater market available if front projection is viable in a typical living room. The more recent projector models are all brighter than their predecessors and some have bright living room modes that maintain good color balance.

To get back to gray vs white screens, I doubt I will ever have a white screen. That is because I doubt I would ever have the space or inclination to setup a dedicated theater room. Therefore I will always have some ambient light issues even with all the lights off at night.
post #19 of 41
Quote:
Originally Posted by tiddler View Post


From the very beginning my goal was to determine if it was possible to integrate front projection into a typical family or living room. To me that is what "Home Theater" really implies.

Golly Todd, where did you ever come up with that concept? Seems that I've been advocating that same idea since 2003, and showing that such can be, and has been repeatedly done a great many times. Effectively too, I'll add without reservation.

And I've shown that in examples that offered up considerably more drastic differences, only to have those examples picked apart for just about every reason that could be thought of to dissuade others in believing that what was being shown was valid and true.

Quote:
Originally Posted by tiddler View Post

With today's brighter high contrast projectors, the use of a gray screen has more to do with ambient light tolerance. If there is any unwanted light falling on the screen, it will reveal the shade of the screen. It is most apparent in areas of the image that are dark.

....and to further that, if the level of projected contrast is combined with both the intensity of the projected Lumens, and the reflectivity potential of the "Gray" Screen, the net result will be an improvement of reflected Contrast, and a shift toward the rejection of the adverse effects of incoming ambient light.

However in any case or situation where as the intensity of such incoming ambient light exceeds the attenuation factor introduced by the specific shade of Gray being employed, the image will still wash out. Of course with directed outside illumination, that threshold is reached much sooner.

But no matter what else...if a Screen is designed to combat such deleterious effects, it's going to perform better than one that is not so capable.

You all want to see some real telling examples? Dated 4-07?

Quote:




Heres a full frontal in high ambient light.



This next shot is taken in a light controlled setting, and is quite vibrant as pointed out.




In the following shots, the Spot lighting in the Video is really bright on the singer, with a yellow colored spot in the second image that was really blasting his forehead in the second shot. All these shots were taken in the dark.
.





The obvious cannot be overstated when observing what is seen in this collage. Even in the ambient light shots, the image seen within the "Strip" is very watchable and basically color correct.



These close-up shots of a Red Guitar show both the loss of detail that comes from a white surface that is receiving even a very contrastive image in not only ambient light, but even in the dark as well. many say "White is just alright", but obviously, it leaves something to be desired....or missing rather. The last two shots are close up "crops" of images taken in the highest possible ambient light in the room.



Now a little bit of Cartoon Contrast Comparison. The center of the image is the full sized MM-LF w/test strip, while the perimeter "dual shots" feature a variety of "with/without test strip" dark room images, as well as ambient combos. (I was trying to save space.)




http://www.avsforum.com/avs-vb/showt...401&highlight=

I've also bumped the original thread....seemed appropriate to do so.


Quote:
Originally Posted by tiddler View Post

To get back to gray vs white screens, I doubt I will ever have a white screen. That is because I doubt I would ever have the space or inclination to setup a dedicated theater room. Therefore I will always have some ambient light issues even with all the lights off at night.

I agree, but a very many other people, most notably those over on both the Screens and PJ Forums, beg to differ....opting to believe that most people will still want to utilize PJs in dedicated environs, and that today's higher contrast / higher lumen PJs need no help from a darker shaded screen.

Well, until we see 5000 lumen PJs with 1,000,000:1 "Native" contrast ratios, there will always be a need to improve the viewing situation...even in a dark room setting.
post #20 of 41
Just to verify, the main full sized screen in the lower images is the mississippi mud/light fushion? Is that similar to silver fire over mirror? I really am leaning towards painting a screen and if that is light fushion on main screen I am sold. I have some ambient light, but nothing like that room.
Thanks again for all your input.
post #21 of 41
Quote:
Originally Posted by malsip72 View Post

Just to verify, the main full sized screen in the lower images is the mississippi mud/light fushion? Is that similar to silver fire over mirror? I really am leaning towards painting a screen and if that is light fushion on main screen I am sold. I have some ambient light, but nothing like that room.
Thanks again for all your input.

Yes the full sized "Light Fusion" Screen is a 96" x 54" x 1/8" Acrylic Mirror sprayed with the original 1:1:1 MississippiMud mix.

UPW
Deep Base
Pearlescence

Simply by adding some Silver Metallic and Polyurethane t the above and your at RS-MaxxxMudd, which is where you want to be, be it on a Mirror or on a Board / the Wall.

BTW, The skinny Gray vertical Strip is a Silver Fire 3.0 coating on a Mirror Scrap
post #22 of 41
Thread Starter 
Just a word of caution regarding screen shots.

I would never try to judge the difference between two screens from separate photographs. How good a screen shot looks depends on a lot of factors not just the quality of the projected image.

If two different screen surfaces are present in the same photograph then you can judge if one is brighter than the other or if one has deeper blacks than the other for the given projected image. If the two screen surfaces are similar in shade and gain, the comparison is quite reasonable. If the two screen surfaces are of significantly different shades then we run into the problem of the projector not being calibrated for one or the other or possibly neither.

You have to be very careful when judging the white levels perceived on gray screen surfaces when there is a white screen surface in the image. Your eyes and brain do a sort of auto white balance based on the brightest white in view. Therefore white light on a gray screen surface is always going to look gray or dull directly compared to the same white light on a white screen surface in the same view or screen shot.

Once you have a full screen of an appropriate shade of gray for your setup and you have performed a contrast & brightness calibration, white will look white. In fact I am often surprised at how white the whites look on my Black Widow 3:1:1 screen (RGB=195-195-195, ~N7.8), knowing how dark a gray it is. I have also had the same stop and stare reaction to how white the whites looked on a Behr ULTRA 4850 N8 gray screen. The only gray surfaces that I have been underwhelmed by, are truly flat finishes like the Behr 1050 tinted neutral gray or Silverscreen. That is why I always recommend a matte base paint for a one can neutral gray screen.

Whenever I read comments like "I don't like gray screens because the whites look gray, etc" I often wonder if the author is viewing a gray and white side-by-side, or if they have not performed the requisite contrast & brightness calibration for the gray screen. Another possibility that comes to mind, is that the projector and screen size they are using does not have adequate foot-lamberts to produce white looking whites. Also, as I stated above, the use of a really flat base paint will often leave you wanting brighter whites.

Just be very cautious when comparing one screen shot photograph to another. The difference you are seeing could be the fact that one was taken with a very good SLR while the other was taken with a camera phone. There is a long list of factors that determine how good a screen shot looks, and the screen surface is only one of them.
post #23 of 41
Quote:
Originally Posted by MississippiMan View Post

Yes the full sized "Light Fusion" Screen is a 96" x 54" x 1/8" Acrylic Mirror sprayed with the original 1:1:1 MississippiMud mix.

UPW
Deep Base
Pearlescence

Simply by adding some Silver Metallic and Polyurethane t the above and your at RS-MaxxxMudd, which is where you want to be, be it on a Mirror or on a Board / the Wall.

BTW, The skinny Gray vertical Strip is a Silver Fire 3.0 coating on a Mirror Scrap

I have experimented with quite a few fabric options, and I do want and feel I need the gray to compliment the contrast for my mitsubishi hc1500. But I do not want to sacrifice the brightness the gray takes.
If I am correct in my reading the best way to do this is by:
Black Flame Light Fushion
Silver Fire (with or with out mirror)
Black Widow (not sure)
I tend to leand toward your mixes because I have been following your stuff for some time.
Question: How is it best to make a BF/LF or SF more portable?
post #24 of 41
Thread Starter 
Quote:
Originally Posted by malsip72 View Post

I have experimented with quite a few fabric options, and I do want and feel I need the gray to compliment the contrast for my mitsubishi hc1500. But I do not want to sacrifice the brightness the gray takes.
If I am correct in my reading the best way to do this is by:
Black Flame Light Fushion
Silver Fire (with or with out mirror)
Black Widow (not sure)
I tend to leand toward your mixes because I have been following your stuff for some time.
Question: How is it best to make a BF/LF or SF more portable?

I think this sort of question regarding mica mixes would be more appropriately in the Silver Fire mix thread. Not that I am recommending any of these complex mica-metallic paint mixes.

This thread was intended to provide a more general demonstration of the fundamental differences between a white screen and a gray screen.
post #25 of 41
Fundamentally speaking, if one wants to see and realize the full range of possibilities and differences between a Gray and White surface, they need to see what it also means to use methods and materials that help offset the 'fundamental' caveats and augment the advantages that using a Gray often presents.

I believe my images show that in much clearer detail than the first one posted at the top does. Especially as to just how much an advantage using the correctly formulated Gray application can be.

But as far as someone asking specific questions pertaining to how/why/when to use a specific mix, then yes...those questions are better served to be delved into elsewhere.

But of course, under those dictates, there then should be no preferential treatment given any other specific application, be it a simple or complex Gray, White, or whatever, on this thread as well. It's all about the differences between the two shades.

Kinda boring and old news, all that......

But even so, a very many Noobs have no clue as to what differences there are and what they mean so in that respect it's not all THAT boring.

Todd,

I apologize. I went back and reviewed the thread. I saw where you posted the first post, then did not post again for 2 years and then only to Bump. How about those Guys...eh? All they wanted to do was to go OT about things like various Grays...Poly....Sharp PJs...everything but a simple demonstration.

And Muzz! The gall! Asking you if you'd change the name of the Thread to:

Flat white vs Gray,vs Metallic Painted screen samples-Picture gallery.

How odd.

I don't blame you for spooking out after that!

And here it all seems to be starting up again because I felt that posting some examples would show how far things have come and what the broadening of the perceived contrast on screen and how effective the counteraction against ambient light has become when employing a Metallic based mix.

I didn't mean to so closely re-enact the past or show the stark "difference" again. I'm sorry.


Ok....I'm funnin witcha a bit. ('cept the "sorry" part.)


Honestly....if I'd bothered to read the thread's available content, I'd have certainly realized there was much missing. I'll not review that past or circumstances of any of it, only make leave to say that much of everything that was said, and shown back then, and that is being said...again, here and elsewhere, has every bit as much truth behind it. People know it. They want to talk about it.

I'm glad to take it elsewhere if you want to restrict the discourse to talking about the basic fundamental differences we see in that first Photo.

I give it another two days.....
post #26 of 41
Quote:
Originally Posted by tiddler View Post

Here is a simple demonstration of what the difference is between a white screen and a gray screen.

In these two photos there is a matte white panel on the left side, and a matte gray panel on the right. In the first photo all lights were turned off. In the second photo I had some lights on in the room. Note that when the lights are all off the gray is almost the same as the white, however, when you have some ambient light the gray is much better than the white.

I don't agree with that assessment at all...leastwise with what I can plainly see on my Monitor. The whites have taken a significant hit, they are not close to being the same at all....and it's plainly noticeable both under cover of darkness and just as pronounced a difference when seen under ambient light. I daresay it's virtually an equally equivalent loss...one that merely keeps pace with the same drop in performance on the white surface.

Quote:


With today's brighter high contrast projectors, the use of a gray screen has more to do with ambient light tolerance.

Not so at all. With the brightness available on today's 1080p PJs, being able to utilize a Gray surface that 'does not attenuate' incoming projected light allows that surface to augment the native contrast of the PJ as seen displayed on such a surface.

This is even more relevant than it was when this Thread was first conceived.

Taking a PJ with 500:1 native Contrast, and by allowing the use of artificial methods both mechanical and software oriented that improve Blacks via attenuating light (...sounds like what a simple Gray does..yes?) means one is employing a "Rob Peter to Pay Paul" mentality. Something is gained, but at the loss of something else that is desirable as well.

Now some PJs do it a lot better at providing Contrast than others, doing such without adversely crushing down detail. Some can do it best when projecting the darkest scenes only,(Epsons) while others do it better overall throughout the entire Gray Scale, but not as good with the blackest content.(Pannys) Still others don't even need such 'assistance' because they have solved the light leakage issues that a tri-panel display often encounters. (JVC)Those PJs are the ones with 35K up to 70k+ "Native" contrast, and it's really only then that one can safely state that a Gray screen's only real purpose and need is to allow for better ambient light viewing performance.

That distinction is almost exclusively a advantage the JVC PJs possess.

But the Playing field all the others compete on can be easily enough leveled out by using a well matched Gray surface that itself does not detract more that it adds to the viewing equation.
post #27 of 41
Quote:
Originally Posted by tiddler View Post

If the two screen surfaces are of significantly different shades then we run into the problem of the projector not being calibrated for one or the other or possibly neither.

You have to be very careful when judging the white levels perceived on gray screen surfaces when there is a white screen surface in the image. Your eyes and brain do a sort of auto white balance based on the brightest white in view. Therefore white light on a gray screen surface is always going to look gray or dull directly compared to the same white light on a white screen surface in the same view or screen shot.

Once you have a full screen of an appropriate shade of gray for your setup and you have performed a contrast & brightness calibration, white will look white.

i don't necessarily agree with everything tiddler stated because i have had an opportunity to see a grey screen outperform a white screen in both controlled lighting and of course in ambient light.

in tiddler's screen shots... the whites take a significant hit in both controlled and ambient viewing... and no amount of calibration will ever allow the grey screen to have equal or better white levels as the white screen... it just aint gonna happen. so yes, take the white screen away and calibrate until your happy with your white levels... just don't put the white screen back up though... you might be disappointed in your whites... again.

in mm screenshots... although mm is working with darker gray than tiddlers and presenting more ambient light to the screen...some of the same can also be said of the ambient light screenshots... but that's to be expected as the more light is present within the room, the more they eye picks on the white matter of the screen itself. the real difference between tiddler's and mm's screenshots is really in the controlled light screenshots... where the white levels of the grey and white screens are performing virtually the same.

here's a different take...

with these cheap phone screenshots... you can clearly see the grey screen outperform the white screen. and NO amount of calibration will get the white screen to outperform the grey screen.



post #28 of 41
I have to say I do agree with pb... but to a point.

I also condone using a gray screen even in a dedicated theater setting, but it is also ultimately up to the individual whether they prefer a gray screen over a white screen, even in a totally light controlled setting.

I do think pb's example isn't the best though. It doesn't show or demonstrate much of a dynamic range and it really can be hard to tell the performance difference. That's not a negative comment, just pointing that out is all.

I totally agree though that you can't have both a gray screen and white screen up together and compare the two... whites will always look better on the white screen and blacks will always look better on the gray screen. Remove the other reference though and now boom... whites look white on even a darker gray.

Here is one of my favorite examples of what whites can look like on an N8 gray:

And a reference of that screen shade:

and some ambient shots with LOTS of ambient lighting...

Now for the mind blower... All of those were on just an OTS (Off The Shelf) D65 neutral gray.

I can show a non-interference (non-mica based application) that performs even better, but the point is a simple OTS gray performs better than some want to admit. Back to what pb was saying... a gray screen can work well even in a dedicated theater. The biggest factor is screen size and projector specs.

Quote:
Originally Posted by pb_maxxx View Post

i don't necessarily agree with everything tiddler stated because i have had an opportunity to see a grey screen outperform a white screen in both controlled lighting and of course in ambient light.

in tiddler's screen shots... the whites take a significant hit in both controlled and ambient viewing... and no amount of calibration will ever allow the grey screen to have equal or better white levels as the white screen... it just aint gonna happen. so yes, take the white screen away and calibrate until your happy with your white levels... just don't put the white screen back up though... you might be disappointed in your whites... again.

in mm screenshots... although mm is working with darker gray than tiddlers and presenting more ambient light to the screen...some of the same can also be said of the ambient light screenshots... but that's to be expected as the more light is present within the room, the more they eye picks on the white matter of the screen itself. the real difference between tiddler's and mm's screenshots is really in the controlled light screenshots... where the white levels of the grey and white screens are performing virtually the same.

here's a different take...

with these cheap phone screenshots... you can clearly see the grey screen outperform the white screen. and NO amount of calibration will get the white screen to outperform the grey screen.



post #29 of 41
Quote:
Originally Posted by pb_maxxx View Post

in tiddler's screen shots... the whites take a significant hit in both controlled and ambient viewing... and no amount of calibration will ever allow the grey screen to have equal or better white levels as the white screen... it just aint gonna happen. so yes, take the white screen away and calibrate until your happy with your white levels... just don't put the white screen back up though... you might be disappointed in your whites... again.

Here is one of my favorite example of what white levels you can get from a N0 zero screen.



I'm sure if I had a white sample as PB suggests in the image I would see how dim my whites really are. I'm also sure the CR would diminish in this N0 zero test by about 1000 times.
post #30 of 41
Might be a favorite, but it's not very acceptable as a example.

Using a photo that contains obviously crushed down Black levels along with the "blown out light" caused by glare from sunlight isn't showing white, it's showing the difference between "glare" and the darkest area of the image where this is no back-lit Sun light. Such an example plays to a situation long pointed out as being a real issue when showing Contrast examples with a camera. The Camera makes the Blacks look blacker than they really are, thereby artificially increasing the appearance of the brilliance of the "Whites". Only if you had introduced an appreciable amount of Ambient light would you have leveled the Playing field between the darker and lighter parts of the image you offered up.

Show a true White, next to a Black for an example even closely worth considering, or in the least something like wbassett's "Top Gun" example.....something that still can show all by itself how a N8.0 Gray is muting those Dress Whites. And everything else for that matter.
That Screenie shows no snap at all. It's flat & dull. I've seem wbassett post far better fare. You too for that matter.

As stated a few times already, you cannot judge the individual performance of a Gray Screen showing Whites, against a White Screen showing Whites because the White Screen's whites will always look...and be whiter.

And you cannot (...or at least should not....) use blown out white Sunlight as an example.

However you can use a White against a Gray to show how much better the latter is at performing acceptably under ambient light conditions, and if that specific Gray has gain, how it will widen the contrast gap that has been shown that exists between a White and a N8.0 Gray which comes in under 1.0 gain, as is shown above.

All this stuff about "White vs Gray' and what Gray is better than another...etc, has it's roots first in trying to achieve better black levels but NOT at the gross expense of Whites and Colors. A True White vs Gray comparison will show that quite handily...and it's my obvious guess that is why you do not see those who have N-something Gray Screens that do not have +gain ever use a White that shows such a comparison . Such Screens comparisons will tell you whats needed to be told....it's just not what some people want to hear/see.

But whether it's a example meant for showing Contrast augmentation or Ambient Light performance, images don't lie. It's not so strange or hard to fathom that when someone does show something out of the ordinary, and that flies in the face of accepted norms, that some will discount or dispute the shown results. But if the shown example between to identical shade is well done and fairly balanced.....or well done with distinctly different shaded screens, if showing a 'difference' between the performance of the two or more examples is the goal, it can be done quite effectively and with complete validity as to the shown results.

As to "having" to depend upon excessive Lumen output to mitigate the loss of image vibrancy and decent looking Whites.....until recently that might have been all too true. For some with no lighting or wall reflection issues to deal with....nowadays if the PJ has at least a native contrast of 1000-2500:1, it is going to produce a great image on a 1.0 gain white Screen.

However on a Gray (...or white...) Screen that is under 1.0 gain, all that can be said is that keeping a PJ on High Lamp mode can help mitigate the all to obvious losses to a point that for many it will not seem to be much of a loss to them at all.

.....until they see that "one on one" comparison.
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