Any ideas how to improve the contrast of LCD projectors? I think the main problem with low shadow detail and black level can't be solved (go and by the latest DLP like Infocus 5700 and you'll be happier). However, it's still possible to help with projection somehow. Some folks have been experimenting with polarizers, and selecting the screen material / color etc. have a huge impact of contrast levels. On avsforum tests a screen (or actually a part of it) painted with aluminium hot paint gave excellent results.
I think polarizer sheets can't help much, but I have one idea for them. Instead of putting the polarizer between the light source and LCD make eyeglasses using them. As you know the LCD light is polarized and therefore if you use a polarizer between you and the screen you can get more the picture fron LCD than the non-polarized ligh from room. One possible problem with that may be the depolarizing effect of the screen. The traffic signs however are painted with a material that doesn't depolarize the light, so that kind of screen paint would work well, though there might be some hot spotting.
I think polarizer sheets can't help much, but I have one idea for them. Instead of putting the polarizer between the light source and LCD make eyeglasses using them. As you know the LCD light is polarized and therefore if you use a polarizer between you and the screen you can get more the picture fron LCD than the non-polarized ligh from room. One possible problem with that may be the depolarizing effect of the screen. The traffic signs however are painted with a material that doesn't depolarize the light, so that kind of screen paint would work well, though there might be some hot spotting.
I think the best way to improve contrast with out changing your lcd is your projection screen. You can go with a grey screen that will give you better blacks but may actually make dark scenes even harder to see. You can try to purchase a silver screen like the silver star (lots of money 
kind of ruins the diy save money idea) or make your own silver screen like you mentioned some people have done on avsforum. It seems a lot of people are happy with silver screens even if they already have good contrast. One more way maybe is the new powerdvd has some clev technology that is supposed to improve contrast automatically while you play a movie gocyberlink clev .
I have the new power dvd and will try it once I have my projector going but don’t know how much it will help.
kind of ruins the diy save money idea) or make your own silver screen like you mentioned some people have done on avsforum. It seems a lot of people are happy with silver screens even if they already have good contrast. One more way maybe is the new powerdvd has some clev technology that is supposed to improve contrast automatically while you play a movie gocyberlink clev .I have the new power dvd and will try it once I have my projector going but don’t know how much it will help.
Two words: Stewart Firehawk
Can't afford to buy it. Will cost many times my projector (panel from BenQ 567s, diy box).
Can't afford to buy it. Will cost many times my projector (panel from BenQ 567s, diy box).
One word: DIY!!!
The paint used on the avs forum is hard to get in Europe. So try some paint yourself. Any big diy shop that can mix (metallic) acryl paints has what you need.
Get 0.5L of acryl metallic base (transparent blueish mettalic paint that they use to mix with different colors to get the paints they sell) and 0.5L of acryl primer.
The metalic paint is often only sold with added color paints. If so buy the metallic with 25% white (results in alu color).
Now its time to experiment. You can control gain (and hotspotting) by adding more or less primer to the metalic.
My metallic was mixed with 25% white at the shop. I used a 10cm roller with fine hairs specially for acryl to apply it.
Adding 25% primer resulted in a very narrow viewing cone, with a gain of more than 1, almost no hotspotting.
75% primer (what i'm using now) resulted in a light grey color with a gain of 0.9 .. 1 .
The beauty of this mix is that you don't even need to use a primer on a flat surface. Its also very easy to roll on and you wont see ANY streaks when you are finished. (The last time you roll over the paint make sure you don't apply any pressure at all, it has to touch it, no more)
The material is use for my screen is used in construction to cover floors and furniture. Its made up of a woven textile with plastic on one side. The plastic side has a slight (random) pattern on it.
I tried the woven side first - lesson learned: any repeating pattern will result in moire interference.
The plastic side was perfect, the pattern actualy helps my picture (larger viewing cone) and it doesn't show unless you look from really close.
As ddog on avs said you can use a few drops of red paint to bring up the reds. The mettalic paints have a higher gain in the green/blue spectrum. I didn't do that myself, you can easily adjust your RGB settings to compensate.
The paint used on the avs forum is hard to get in Europe. So try some paint yourself. Any big diy shop that can mix (metallic) acryl paints has what you need.
Get 0.5L of acryl metallic base (transparent blueish mettalic paint that they use to mix with different colors to get the paints they sell) and 0.5L of acryl primer.
The metalic paint is often only sold with added color paints. If so buy the metallic with 25% white (results in alu color).
Now its time to experiment. You can control gain (and hotspotting) by adding more or less primer to the metalic.
My metallic was mixed with 25% white at the shop. I used a 10cm roller with fine hairs specially for acryl to apply it.
Adding 25% primer resulted in a very narrow viewing cone, with a gain of more than 1, almost no hotspotting.
75% primer (what i'm using now) resulted in a light grey color with a gain of 0.9 .. 1 .
The beauty of this mix is that you don't even need to use a primer on a flat surface. Its also very easy to roll on and you wont see ANY streaks when you are finished. (The last time you roll over the paint make sure you don't apply any pressure at all, it has to touch it, no more)
The material is use for my screen is used in construction to cover floors and furniture. Its made up of a woven textile with plastic on one side. The plastic side has a slight (random) pattern on it.
I tried the woven side first - lesson learned: any repeating pattern will result in moire interference.
The plastic side was perfect, the pattern actualy helps my picture (larger viewing cone) and it doesn't show unless you look from really close.
As ddog on avs said you can use a few drops of red paint to bring up the reds. The mettalic paints have a higher gain in the green/blue spectrum. I didn't do that myself, you can easily adjust your RGB settings to compensate.
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