Originally Posted by vpersaud
And I thought both the Epson 5010/6010 and JVC would have plenty of light output to not need 2.4 gain... I am considering about 120-130" 16:9 (I gave up on the 2.35 CIH setup).
You should definitely look into the HP 2.4 gain screen for that screen size, the JVC does not have enough brightness if you want the lamp to last a long time.
1) There is no such thing as enough light output when talking about lamp costs and how long a lamp might last. The JVC has a heavy manual IRIS (aperture) that lets you clamp the brightness way down, so it would be hard to make it too bright. Even if it is too bright the first 300 hours, it is unlikely to be too bright after that. Add to that 3D (even if you only watch occasionally) and that makes it even more needed.
2) Even a good lamp loses a lot of brightness at 1000 hours, on average at least 25% to 50%.
3) You can buy an ND filter for $50 if you really need to, and this can be used each time you get a new lamp and want to tame the brightness until the lamp has worn in.
4) One of the #1 complaints on the JVC is it not being bright enough after the lamp wears in, yet these same people will try to tell you that X and X screen size is fine with X and X gain. My response is that 4x gain with an ND filter would be do-able with the JVC if such a screen existed without side effects (They do exist, but not without side effects).
5) A Da-Lite High Power screen raises both white and black levels at the same time, so you maintain the same contrast. In most rooms, it will look as good as much more expensive screens (and IMHO better since you will get a brighter image longer). If you bought an expensive 1.0 gain Stewart or something, it might look a little better for the first 200 hours, but Actually in most rooms, the Da-Lite HP screen will increase intrascene and ANSI contrast because of rejecting light, because even as perfect as some of us think our rooms are, even black material still reflects some light, and the Da-Lite rejects it to some degree.
6) The only real alternative to an HP screen that can greatly increase brightness without side effects are extremely expensive screens.
7) Even if you believe the lamp issue is fixed, not having gain makes you more susceptible to the issue and even in a best case makes the lamp last a shorter time period increasing replacement costs.