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Discussion Starter · #1 ·
I highly recommend this for any digital machine.

This really works. Some benefits using such a screen are the gray hides the pixel structure for those using lower res machines so your pixel structure is gone. This is due to the fact the gray is the same color as the border that makes up the pixels. Another benifit is it also masks any video noise, it enhances colors and gives the dila the blacks and rich colors I saw using the 3 chip dlp.

Your dila will very closely resemble a CRT projector.

You can test this yourself. Just paint a large piece of cardboard flat gray and hold it up to your existing screen. You will be impressed and I think you will become a user.


I made a screen just for testing for this purpose. I painted the screen flat gray. Not to dark but a shade darker than light gray.

The improvement on the blacks and depth to the picture were huge.

I was about to invest in a 3 chip dlp because I liked what I saw when I had the Runco 3 chip for a couple of days but I will say this looks every bit as good. A very rich picture.


While im sure using a color meter the gray has an effect on the gray scale, I will say to the human eye I will defy anyone who sees this in use to say the whites are not white.

While watching a movie the whites are pure white not gray. You cannot tell you are using a gray screen till you turn off the projector and turn up the house lights.


Also unless you are currently using a high gain screen you will not notice any light loss verses a matt white screen. The dila produces plenty of light and then some.


The problem now becomes how do you get a gray screen fabric. Stewart makes some. This is used in some of the special rides in Disney/universal studios but the material is not cheap.

Right now you will have to use your imagination. But it is well worth it.


I am ISF certified and know that by the rule book gray is a no no and I might get slammed by some of the purest on this but I am telling you it is a huge improvement.

Your projector will come alive with rich colors, depth and blacks.




[This message has been edited by Alan Gouger (edited June 18, 2000).]
 

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Alan,


I admire your creativity with screens. You tend to push the envelope, looking for a better mousetrap. I've thought this before, when you work with manufacturers like CI, Chromalux etc. Even if every one didn't pan out, you were there ready to make it available. That's why you have so many fans.


More people should be like you.


Ted
 

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I am happy that someone with credibility has actually tested this out.


Next the inevitable questions. What projector, how bright, what paint, etc.

If you decide to post in the screen forum, let us know.
 

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There are older screens that were used with 8mm film

projectors that have a grayish/silverish colored

screen material.

Is that going to give the same effect?

I think I know where to lay my hands on one.


Bob Wood
 

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Currently, I am shooting my D-ILA on a heavy knockdown sheetrock wall painted a greyish green. I tested many colors and found this the most effective. I was reluctant to post what I had done fearful of the lectures I might receive relative to color purity and so forth. The bottom line is that the image looks great. On a second note, I have heard arguments pro and con with perforated screens. As strange as this sounds, I think a non uniform surface used as a screen aids in contrast and depth. I also painted a flat surface with the same grey/green paint I mentioned above and found the image looked better on the tectured wall. Strange but true.
 

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Discussion Starter · #6 ·
Robert

The screen you are talking about is a silver screen. It will not work the same. It will be better than a white screen but not as good as the gray!
 

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Alan, have you tried this with your Davis unit? Is the Davis bright enought to make this practical for it as well?

 

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Well this is very interesting. Especially if you had some large, wide wooden boards, you could spackle the seams between them, paint the surface gray and use it it for a screen. Or, just paint the wall gray. The wall behind my screen is a very dark gray. I have projected onto it and I didn't like the look. But a ligher gray could work much better. Alan, what kind of paint are you using? Any other experimenters besides Alan and Don want to come forward?


Larry


[This message has been edited by Larry Davis (edited June 18, 2000).]
 

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Discussion Starter · #9 ·
Anyone painting your own screen use only neutral colors.

I added a little black to white and mixed then together to arrive at the gray I am using.

Or you can just buy gray.


Yes it will work fine with the Davis. The Davis is plenty bright. This will completely eliminate the 800x600 pixel structure.
 

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For additional discussion check www.avsforum.com/ubb/Forum9/HTML/000309.html .


Other concepts I have been thinking about is to use a translucent background such as tracing parchment over a black backing. This can give a grayish look which can be adjusted. Conceptually it could provide similarities to a rear projection system, just requiring brighter projection intensity since the image is back-scattered instead of forward-scattered.


Has any one tried front-projecting on a rear projection screen with a black background?


Don Giberson,

How did you mix your grey green?



[This message has been edited by kelliot (edited June 19, 2000).]
 

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Quote:
Originally posted by Alan Gouger:
The problem now becomes how do you get a gray screen fabric. Stewart makes some. This is used in some of the special rides in Disney/universal studios but the material is not cheap.

Right now you will have to use your imagination. But it is well worth it.


I am ISF certified and know that by the rule book gray is a no no and I might get slammed by some of the purest on this but I am telling you it is a huge improvement.

Your projector will come alive with rich colors, depth and blacks.
What do you think of Da-Lite Super Wonder Lite? It seems to be a grey/tan color. Christopher Crim's screen material test at http://crimdom.net/home-theatre/screens.html uses it. He noted that it lessens the effect of ambient light under high light conditions, but doesn't think it looks better in a properly darkened room. It also apparently isn't available in sizes greater than 70" on any one side. His screen shots show it looking a lot like Da-Lite Da-Mat. The major weakness of his 'screen test' design, as I see it, is that he did not recalibrate his HT10 for each different type of material, rendering the comparisons problematic.


------------------

== Tove

A rainbow rat...a checkered cat
 

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Screen for Mosquitos?


I have made this test:


I put a non glare that I is used in front of the computer screens and looks like the type of nylon used in women's pantyhose, but didn't obtain good results. I made a test painting a black board a light gray and the results are very good if I could leave the image small enough to have plenty of light from my 800 lumens projector.


Right now I'm using a blackboard that I painted first with flat black, acrilic paint using an air brush and then I painted it flat acrilic white on top but not various coats so I wouldn't lose the black background so in the dark it looks more gray than white, but when it's exposed to the light of the projector it looks perfectly white. Another thing is that the texture that the paint left seems like the lemon skin so you have small perturbances that difuse the light and can diminish the visibility of the pixels of the projector. I'm very happy with the results but looking for something better, I will try paniting with clear white intead of flat white, I'll keep you inform.


Federico
 

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Alan,


Can you post a picture of the shade of gray you are taking about....then we can all trek down to the local Home Depot or Sherwin Williams and have them match the color!


Michael
 

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Quote:
Originally posted by Archangel:
Alan,


Can you post a picture of the shade of gray you are taking about....then we can all trek down to the local Home Depot or Sherwin Williams and have them match the color!


Michael


Perhap a neutral gray card is the right shade. I forgot what percentage that is. In photography they have different % grey cards. First I went to a photography supply store to get this card, then I went to sherwin williams and they matched it perfectly for me. This was to paint the wall behind my RPTV the proper color (then shine a 6500k light on it).


Perhaps a similar approach can be taken so that everyone uses the "right" shade of gray for their experiments.


RicardoD

 

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If you make your own gray from black and white, beware the white. Often it contains blue. And "gray" often has other tints as well.


Noah


BTW, Alan, this is totally cool. I really admire your initiative and your refusal to be bound by doing things the "right" way.


[This message has been edited by noah katz (edited June 19, 2000).]
 

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This thread is really quite exciting and a perfect example of why I no longer read the internet home theater newsgroups (i.e. attitude flamefest bonanza)and call this my home! Alan I agree - always burning the midnight oil aren't you http://www.avsforum.com/ubb/smile.gif


Anyone of you grey/green screen folks brave enough to take some screen shots and also with lights on to show what these look like?


Am I to understand that hanging a wooden framed sheetrock screen painted with grey paint is going to make my new projector shine? Couldn't do this before with my 8" crt cause lumens were lacking, but with the new 1000 lumen DLP on the way I think I just may try it - post the recipe and I'll be the guinea pig http://www.avsforum.com/ubb/eek.gif
 

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Federico, Phil_Wms

With regard to netting. Theorically, screen/netting should be over a white background and be fairly dark and transparent (>75% transmission). For example 1 black nylon woven with a spacing of 10 mil over bright white should attenuate ambient quite well due to shadowing.


Air brushing is a good idea. If the drop size is right, it will also create some shadowing. How do you get it uniform. I guess one could use netting as a spray mask also to create some unique screens.


Of course it the appropriate color gray works, that is even better beacuse of the cost and ease of implementing. My guess is that a 50% grey with a 2000 lumen projector would still give nice bright whites, but would attenuate the ambient nicely. (Mitsubushi has a new 3000 lumen projecter which will be out in the fall that I saw at Infocomm. I wonder if it has two lamps?)

If any paint people are in the audience, how about ground charcoal or lamp black in a white base. At least it does not have blue in it.


Ken Elliott
 

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Hello to all,


This is a great concept, but there are an infinite number of shades of grey, so the one that works for you I'm sure will be dependent on the equipment you have and how much you want to diffuse the light. I would imagine this concept of screen color would indeed not be acceptable w/ISF, but who cares, if it works, so be it. This is Alans idea for D-ILA, not CRT. D-ILA has the brightness factor already. CRT couldn't handle the darker screen, correct? Sounds like this post will be going for a good while. Can't wait to get my D-ILA so I can post results w/you guys. Good luck to all.


Chris
 
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