Originally Posted by CaspianM
Hi gain screen would put you back to square one. Why to buy a hi contrast pj with deep black level then boost that with a hi gain screen?
The main reason is in cases where that high contrast ratio isn't usable without a high gain screen (because ft-lamberts for white would be too low), so you would have to settle for lower CR (or maybe a different technology) if you aren't willing to use a high gain screen. Or so you can have a big screen at that same CR and still enough ft-lamberts for white. In the case mentioned, a person might have to settle for 1300:1 on/off CR if they were only willing to use a 1.0 gain screen, but could get 4300:1 if they were willing to go with a high gain screen that gave them say 2.5 gain at the main viewing position. They could also use that for movies and then open the iris up for some other things where they wanted higher ft-lamberts. For instance, if they preferred 12 ft-lamberts for movies, but 30+ for certain video games where they were willing to live with lower on/off CR. Or just wanted to open the irises up for things like the SuperBowl with lights on. If they were already at max lumens there wouldn't be an option to open up the irises for much brighter images for those other things compared to how they watch movies in the dark.
Originally Posted by GlenC
High gain screens would not be my direction. I would prefer to stay with a matte white smooth screen, now that we are in the 1920x1080 realm. Gain coatings compete with image resolution.
The High Power has very high image resolution.
As far as that 10+ gain screen, I tried it (the Mocom), but it has one of those silver surfaces and I don't like the speckling I see from any screens like that (the SilverStar for instance). I also dislike the SuperNova for the same kind of thing.
The H79 worked pretty well with the High Power and I preferred that. I went about as far down on the irises as I could go, but also had 4 irises total. Starting from the bulb, one red and one clear at one location prior to the DMD and then another red and clear at a location in the lens (after the DMD). I also optimized them for the particular zoom and offset I was using. They would need to be a little more general with if the zoom and offset weren't known.
My preference at this point (and even then) was for somebody to do a dynamic iris system that is as good as what Sony has on their projectors, but with a DLP. That is one way to get high lumens and high on/off CR. But 2 dynamic irises working in unison might work best with a DLP and not sure any company will go to that expense anytime soon. They do it for their irises that can be adjusted (by not dynamic) with one prior to the DMD and one after, but I'm guessing the upcoming BenQ with a dynamic iris will just have one of them moving. And I hope it works as well as Sony's implementation, but not banking on it yet.