[whiteyford]

I'm looking for opinions on grey back or white back screens. Which is likely to give the best picture? So far everyone I've talked to is split on which is better. Any help would be appreciated.

 

[Tryg]

If you are a video purist go with white. If you can control your lighting you don't need grey.


If your fastinated with the deepest blacks and are willing to compromise the rest of the picture go with grey.


Under ideal circumstances the average person may not be able to tell the difference if there is nothing else nearby to compare it to. If you must see for yourself take a board and paint one half white and the other half light grey. Put it up where you screen will be and watch video on it for a week or so. It should be clear at this point which one you prefer.

 

[jacksonian]

Tryg, can you comment on how the rest of the picture is compromised?

 

[brothermaynard]

To add to what Tryg said, your decision will also have a lot to do with how many lumens you have because a gray screen will not look as bright.

 

[Tryg]

First off, I want to say that it's all relative. somewhat...


Here's a good illustration that I've stole from Movie Bear

http://bearmovienights.home.attbi.com/mult.gif


Now, projected white on a grey screen will never be white. It will always be gray. But your perception can make you think it's white if no other references are present.


So what does a grey screen actually do? Although is does lower the floor for black it also lowers the ceiling for whites too....and of course everything in between. So are colors accurate? NO. Some say they become overly saturated. I think this is a misuse of the term saturated as I prefer to think they have taken on a darker hue of the original color.


What's the most accruate coloration? a white screen.


Then how can some find Grey screens benefitial? Because it's all about perception. If all you have in the room is a grey screen your whites will likely look white to you.


If you've done many side by side comparisons though, you start to formulate a reference memory. Then when you look at a grey screen all you can think of is why the colors and whites look off. Fortunately humans have short memories so I think this eventually adjusts to think everything is accurate again. I'm only a month into the test driving of a grey screen and I still can't shake it, but I'm trying...


It essentially becomes a personal preferance. I personally like white screens. I'm not willing to compromise my whites and colors just to get slightly darker blacks.


Grey screens became popular because of the diffeciency of digital projectors with blacks. So, with digital projectors getting better are grey screens gonna go bye bye? Yes and No. Grey screens can help when you can't control the lighting in your room. The blacks on your screen can only be as black as the screen when no light is projected on it. So, starting with a screen that is already darker(grey screen) gets you that much closer to a satisfying black level for your ambient light conditions. Generally if you have control over your ambient light, and you have a decent CR projector, you don't need a grey screen.


Here's a good color information link I've used in the past
http://www.techcolor.com/help/rgb.html

 

[kraigk]

I concur with Tryg. I've got a Parkland diy setup that I'm quite proud of. Stewart sent me samples of Greyhawk and Firehawk and when draped over the Parkland screen for testing everyone I have shown this to has voted for the Parkland. The concensus is the white screen is brighter and more true in color.


Bear in mind I have a basement room with no windows, a Yamaha LPX-500 which does blacks pretty well and I watch hdtv almost exclusively. Were this setup in a less light controlled room I might be wanting the grey screen.


I'll be posting some pics of this setup soon.


-kraig

 

[darinp]

Quote:

Originally posted by Tryg If you must see for yourself take a board and paint one half white and the other half light grey. Put it up where you screen will be and watch video on it for a week or so. It should be clear at this point which one you prefer.

I don't think that many people would consider putting the 2 shades side-by-side and watching them at the same time for a week to be a good test. The best analogy I ever saw from anybody about this was trying to compare Coke and Pepsi by using one straw on each side of your mouth and drinking them at the same time. Just about anybody would compare them one at a time and by doing both color shades at the same time you are not allowing your eyes to adjust to the way things will really be once you decide on one. Once you decide on a screen, you won't be watching with another brighter or dimmer image next to it for comparison, so doing it here will change your perception. You also might decide to calibrate your projector for the material you pick, which doesn't really work for 2 different materials at the same time.


White is relative. The 1.3 gain screens are "grey" compared to the 2.8 gain Hi-Power, which is "grey" compared to the 6.0 gain screens (on axis of course). We call screens "white" if they have a gain of 1.0 or more and "grey" if they have a gain of less than 1.0, but that is somewhat arbitrary, IMO. The HCCV screen from Da-Lite looks white to me when I bright light is shined on it.


Much of whether you want a higher or lower gain screen depends on whether your projector is bright enough for you and also how you feel about black levels. If your projector is too bright for your tastes in your setup then you need to find some way to lower the brightness. One way is a neutral density filter, another is a lower gain screen. If you are starving for brightness and can handle the black level change, then a higher gain screen is probably in order.


Tryg,


If you had combined the grey screen with a brighter projector, then you shouldn't miss your old "whites", since they could be exactly the same. In your case it sounds like you are missing the bright images that you had. Some people are more sensitive to black levels and some to white levels.


BTW: I don't have enough experience with the Firehawk to really talk about the colorshift issues.


--Darin

 

[Tryg]

darin is all relative....that is, to the projector that you have.


Yes, blasting a grey screen with enough lumens will give you the same perception as the white screen. It will still be grey but you may not percieve it. But now we're not talking about different projectors. Also, this would only be true for the whites, the colors will still look different. A good example of this is the Firehawk. It makes up for the dull whites with the reflective splatter coating by bringing up the gain, but the colors are definately a darker hue.


Also the comparing Pepsi vs Coke with two staws at the same time does not hold any water with me. Although this was a cute analogy it is wrong.


To compare one product to the next you MUST have them side by side. Will this be your final perception after one is removed? No, but it does give you an idea of what each product does and it's limitations.


Although your perceptions change to the overall environment, the product remains the same.


Apply this same theory to the masking of your screen, changing of lighting or any other environmental change.


BTW. our perceptions tells us that the sun rotates around the earth. Until you look from another perspective this falseness may satisfy you.

 

[darinp]

Quote:

Originally posted by Tryg darin is all relative....that is, to the projector that you have. Yes, blasting a grey screen with enough lumens will give you the same perception as the white screen. It will still be grey but you may not percieve it. But now we're not talking about different projectors.

Or different settings for the same projector. When you say that it will still be grey what do you mean? Are you saying that if you put 1000 lumens of white on a 0.5 gain screen and 500 lumens of white on a 1.0 gain screen, the one on the 0.5 gain screen will still be grey, but you won't perceive it? In either case you are getting the same intensity of white light, so will the light that reaches your eye be white or grey? It is the light that reaches your eyes that really matters, so please explain how one is grey to the viewer and one isn't.


BTW: That last one was a trick question. There is no definition of intensity for white light. Do you agree that a 1.0 gain screen is more grey than a 2.8 gain screen? Or would we call that "less white"?

Quote:

To compare one product to the next you MUST have them side by side. Will this be your final perception after one is removed? No, but it does give you an idea of what each product does and it's limitations.

It depends on what your goal is. If you are trying to do a scientific like study of the characteristics of each material this is much different than if you are trying to figure out which material you want to be viewing on. For this what really matters is which you will prefer when the other one isn't there? Isn't that ultimately what the person who started this thread wants to know?
Quote:

Apply this same theory to the masking of your screen, changing of lighting or any other environmental change.

For testing masking I would not even consider masking half the screen and not the other and viewing movies this way to determine which I preferred. I think that would be a ridiculous test. I would test with masking and without, not half and half.


--Darin

 

[Tryg]

I was speaking of masking around your screen.


Now back to which is grayer 1.3 or 2.5 gain? Neither they are both white. It's the intensity that we are talking about. With enough intensity, an alone grey screen can look like 1.3 but only at the non colored upper end.


I will search for an illustration or try to make one so as to make this understandable.

 

[darinp]

Quote:

Originally posted by Tryg I was speaking of masking around your screen.

So was I. Maybe I misunderstood your comment. So, what did you mean when you said to apply the same theory to masking? I thought you meant the theory of viewing both at once.


--Darin

 

[darinp]

Quote:

Originally posted by Tryg Now back to which is grayer 1.3 or 2.5 gain? Neither they are both white. It's the intensity that we are talking about. With enough intensity, an alone grey screen can look like 1.3 but only at the non colored upper end.

I am interested in an illustration or some other explanation. You say only at the non colored upper end, so lets try the lower end. With multiple layers the Firehawk physics get a little complicated. Take a pure grey screen with a 0.9 gain. All this screen should do is return 90% of any light (photons) that are shined on it and this should apply equally to red, blue, and green.


Now shine 130 lumens of white on it and 90 lumens of white light on a 1.3 gain screen. How does the light that reaches the user vary between these two cases?


Another question. Off axis a high gain screen returns less than 1.0 gain. How does the light a user sees at 0.9 gain position from a high gain screen differ from the light from a pure 0.9 gain screen? If they don't differ, then is a white screen grey off axis?


Do you have a definition for white? If your bulb ages and the lumens go down does that mean that you don't see white anymore?


--Darin