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post #31 of 41 Old 01-20-2010, 06:37 AM
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Quote:
Originally Posted by MississippiMan View Post

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.

MM

As always in your fervor to reply you failed to read the post. The screen shot in question was a Muncell number N-0 not a N8 or N9 as most use that clearly crush whites as you and PB always remind us. And that image was indeed taken with massive amounts of ambient light. In fact the room was brightly lit and I added in a couple flood lights pointing at the screen a few feet away.

The photo contains 000 blacks and 255 255 255 whites, and I cant say for sure the cam didn't do some auto correction, but I am sure the image posted fuzzy and all was what my eyes saw at the time of the photo.

There was no desire in taking this screen shot to show any PQ issue other than to prove once and for all that Gray screens Do not diminish Whites. They also Do not improve native CR. and They do help preserve CR when ambient light is in play. And all this can be done without high gain if you have enough lumens, or in this case foot lamberts.

Human eyes have perception of contrast and variable iris control. Just as cams and camcorders have. When you walk over and press your face to the screen wall to judge that no off angle gain was lost your eyes have opened several f-stops.


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post #32 of 41 Old 01-20-2010, 06:42 AM
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Quote:
Originally Posted by bud16415 View Post

MM

As always in your fervor to reply you failed to read the post.

No you failed to note that in the instance about a N8.0 I was talking specifically about wbassett's Top gun shot. I never stated that the screen you showed was N8.0, only that the content would mislead anyone who saw it because of the extreme glare-induced white.

To quote James T. Kirk;
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post #33 of 41 Old 01-20-2010, 06:54 AM
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Quote:
Originally Posted by bud16415 View Post

MM
And that image was indeed taken with massive amounts of ambient light. In fact the room was brightly lit and I added in a couple flood lights pointing at the screen a few feet away.

That should have been included, but as such it was not....it's not something that can be accounted for.

Quote:


The photo contains 000 blacks and 255 255 255 whites, and I cant say for sure the cam didn’t do some auto correction, but I am sure the image posted fuzzy and all was what my eyes saw at the time of the photo.

How big was that image, Bud? Was it you little "Black" sample? and those "Whites' are not "white' as much as they really represent the total lack of any contrast.

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There was no desire in taking this screen shot to show any PQ issue other than to prove once and for all that Gray screens “Do not diminish Whites.”

Yes...they do attenuate whites. Just not nearly as much as when you shoot 2000+ lumens onto a postage stamp sized screen.

Quote:


They also “Do not improve native CR.”

No one says...or has said that...and it's only mentioned by those who want to redirect attention that say that such has been said.

Quote:


“They do help preserve CR when ambient light is in play.” And all this can be done without high gain if you have enough lumens, or in this case foot lamberts.

Not many use presentation-oriented PJs anymore. And you get Foot lamberts from the Screen...not the PJ....so if the Screen cannot reflect enough light to provide them, they are not there.

Quote:


Human eyes have perception of contrast and variable iris control. Just as cams and camcorders have. When you walk over and press your face to the screen wall to judge that no off angle gain was lost your eyes have opened several f-stops.

With that Screen you'd be looking down your nose to see the edges of the screen.

To quote James T. Kirk;
"I'm laughing at the superior intellect"
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post #34 of 41 Old 01-20-2010, 06:56 AM - Thread Starter
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For anyone new to the forum, Bud posted the following image in the thread Breakthrough in ambient light rejecting screen



Here is the spoiler.
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post #35 of 41 Old 01-20-2010, 07:06 AM
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Quote:
Originally Posted by MississippiMan View Post

No you failed to note that in the instance about a N8.0 I was talking specifically about wbassett's Top gun shot. I never stated that the screen you showed was N8.0, only that the content would mislead anyone who saw it because of the extreme glare-induced white.

Projectors output light (Period) if the media is film or analog or digital, DLP or LCD its just light. it ranges between white and black (no light) and stays in the visual spectrum of colors. If the person capturing the image on film or in a digital manner films bright daylight. The film doesn't capture and store daylight, nor does the projector output sunlight because that's what the image was captured from. The brightest white on film is when the exposure and development of the film left the film clear in that spot. The brightest white in digital is when the cam said that's it record that pixel as all on. Likewise the darkest black in film didn't expose the film and the darkest black in digital tells the pixel stay shut off.

My test shot could have been of a black and white ANSI checkerboard and the image would have been even more boring but the white no more white.

If we want to talk about deceiving it would be someone posting a screen shot say of a sports bar that also included a lot of the room and say a couple doors open to the noon day sun streaming in showing massive CR ratio within the photo that wasn't within the image being shown on the screen.


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post #36 of 41 Old 01-20-2010, 07:34 AM
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Quote:
Originally Posted by bud16415 View Post


My test shot could have been of a black and white ANSI checkerboard and the image would have been even more boring but the white no more white.

The image is not a valid example of anything except that you can drive an image onto a black surface if the illuminated area is small enough and you have enough lumens. If you would have instead zoomed the image out to full size with that little area contained within the center, it would have been almost gone. Those "Whites' as you call them would have looked like a very dark Gray, and everything else would have been virtually non-existent.

You know that....that was the intent of your whimsical posting in the first place.
What is subject to conjecture is why you felt that image had any relevance to this thread?


Quote:


If we want to talk about deceiving it would be someone posting a screen shot say of a sports bar that also included a lot of the room and say a couple doors open to the noon day sun streaming in showing massive CR ratio within the photo that wasn’t within the image being shown on the screen.

Those shots, and similar shots plainly showed a degree of ambient light that no one else has ever dared to allow be present with their screen shots....even you, and the inclusion of the light from the Door in one shot was strictly to illustrate exactly where that light was coming from. And why? Because that's what people wanted to see. I took several shots that excluded that light source from the Camera's field of view and they looked exactly the same. And everything was spelled out and described, not presented as a "guess what this is" posting.

Most important here now is that no one talked about anyone "deceiving" anybody, only that such an example would mislead the uninformed as to believing that the example was of a normal sized screen and the results comparative to what they might expect to see themselves. Not many Noobs would note the "0.0" designation, and more than a few regularly posting members as well, I'd venture. I said only that the example was not valid because of what it consisted of and how it was effectively done. That sort of commentary as you just used is rhetoric used mostly by those who feel the need to redirect attention. I'm truly sorry you felt the need to say such a thing.

To quote James T. Kirk;
"I'm laughing at the superior intellect"
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post #37 of 41 Old 01-20-2010, 07:39 AM
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Just in case you need a white reference point. Heres a pic of some whites coming from Roscos White White, at 180".




one more.....


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post #38 of 41 Old 01-20-2010, 07:49 AM
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Those are nice. Can you take them again from 12' - 14' away?

If they come out looking a bit dim, shoot them at between 500-800 ISO, and employ your Zoom just enough to compensate for any excessive amount of incoming light your camera picks up.

To quote James T. Kirk;
"I'm laughing at the superior intellect"
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post #39 of 41 Old 01-20-2010, 07:56 AM
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Quote:
Originally Posted by MississippiMan View Post

Yes...they do attenuate whites. Just not nearly as much as when you shoot 2000+ lumens onto a postage stamp sized screen.

Attenuate: become weaker, in strength, value, or magnitude

Above is a common definition of the word we like to use a lot in the forum. And some people I believe think it has a different meaning.

If we listen to a recording of Bing Crosby singing White Christmas with the sound level set to 10 on our record player. We all go hey that's Bing singing White Christmas. If we then Attenuate the play back to 5. Do we say hey that's Alvin and the chipmunks singing White Christmas, or Barry White. No it's still Bing. Just with the brightness turned down.

Likewise turning the intensity down with a neutral gray screen or a ND filter at the lens or going into the projector settings and adjusting brightness. Our eyes adjust and White is once again White. Thus the reasoning behind (Neutral) in front of the word gray or the word filter. Neutral has no change in the information. Just a change in strength, value, or magnitude. There isn't a gray push as if the screen had a blue gray color and resulted in a blue push when compared by eye to a white screen. That would be like adjusting the sound level of Bing by adjusting the treble knob.


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post #40 of 41 Old 01-20-2010, 08:47 AM
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Quote:
Originally Posted by MississippiMan View Post

Those are nice. Can you take them again from 12' - 14' away?

If they come out looking a bit dim, shoot them at between 500-800 ISO, and employ your Zoom just enough to compensate for any excessive amount of incoming light your camera picks up.

Actually took the picture from 15' away, but did use a very slight zoom on the pic. Will take again without the zoom. Ill try the ISO settings you suggested. Thanks
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post #41 of 41 Old 01-20-2010, 10:21 AM
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I_am_legend

Your screen shots are quite nice. And show great ANSI contrast within the image.

To give you an idea of how they measure using an eye dropper tool to measure the black and whites. With the range being between 0 and 255 your whites on the slope facing the sun are around 248 and the black on the backside in the shadows is around 18. The black off your screen to the right measures about 4. Some of the snow that still looks white just not as bright have RGB numbers where they are all close to the same and numbers like 210 and 200.

Now is this exactly what you are seeing we don't know. But from screen shots I have taken I would guess you are saying they are pretty close. And the kind of differences we are looking at are not really that great with these Neutral gray screens compared to your white with the lights out in the room. And in any case you are surpassing most movie theaters.

Now in comparison my misleading screen shot I posted from The Duke's, shows whites at 254 and blacks at 0. With lots of ambient light. And yes this is not very possible to do on a large scale screen. It was done to take a concept to its extreme limits for the point of illustration and education, and also entertainment.

A more realistic screen shot of mine would be this one at 110 screen size and far fewer foot lamberts. Whites at 254 and blacks around 20. In lights out conditions with a fairly dark gray screen of less than one gain. I didn't take an ambient shot but what you would see is very similar to what Todd posted in the OP of the flowers.



The notion that you need a super projector Business variety to do this is not as true as it once was. There are quite a few projectors that have been measured very bright. The misconception I think is many people assume they need brighter with ambient problems but they don't think they can get white off gray. And gray is the other half of the equation.


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