You are on the right track here, IMO. I would not even consider the ST100. It will look almost identical to the ST130, but a little dimmer.
What you may not know is that the human visual system does not perceive increases in image brightness the same as a light meter, which essentially counts the number of photons. If you double the image brightness, as measured by a meter, you would perceive a much smaller increase than a doubling. I don't remember the exact figures any more, but you might perceive a 25% or 30% increase. I'm sure someone will look up the exact figure and post it to correct my figure, but the principle will be the same.
The point is that you should not give away any image brightness without getting something very substantial in return. You are proposing a very large screen. 3-D causes a huge penalty in image brightness. Your bulbs output will drop by 50% during its projected lifetime. It is easy to make the image dimmer (though you would likely never choose to do that), not so to make it brighter. Your concerns are well founded.
At 2000 lumens from the VW-1000, you should get acceptably bright 3-D especially when the bulb is new. You are wise to be thinking down the road. I would project that near the end of your bulb's life, your 3-D image will be looking too dim, even with a 1.3 gain screen.
Years ago I measured a variety of screen materials. The ST130 is color accurate. When measured from a variety of angles the color and image brightness shift so subtly as to be unnoticable in any practical sense. Stewart's specs on the material are accurate, which can't be said for most of its competitors.
Most screen materials with a gain above 1.3 create a greater compromise when it comes to color and brightness uniformity, and in off-angle performance (standing off the the side of the screen and viewing it from a 45 degree angle). However, even those compromises are worth it if that is what it takes to get a bright enough image.
When I plan an install, I plan to achieve at least
14-15 foot-lamberts (after calibration) at the screen center with a 100 IRE (white) window. More is better. That allows you to get the projected life out of the bulb, at which point the image would be at 7 foot-lamberts. Below this point most people begin to subjectively feel the image is getting dim, in my experience. All the above is for 2-D content in an ideal theater. When you consider 3-D, you should plan on at least doubling the initial image brightness needed because 3-D is going to reduce image brightness by at least half, generally speaking.
As far as other screen materials:
The High-Power is excellent, but only if the PJ is shelf mounted at the same height as the center of the screen.
The Silverstar is super high gain, but some people perceive a sort of "texture"
to it that is objectionable. I don't, personally, but I know people who do.
There was one other higher gain screen material that tested out very well, but I can't remember what it was. I think it was a Vutec material and it measured out at 1.6 gain, with uniformity measurements similar to the ST130. I remember that at a 45 degree angle it still measured out at 1.3 gain. If you were to do a search on my past posts, you would come across those screen measurements from several years ago. All the other high gain materials that I measured caused compromises that would be detectable. Not a deal breaker though, if that is what it takes to get acceptable image brightness for a customer who refuses to accept a smaller screen. Stewart failed to provide me screen samples, when I did these tests, so the only Stewarts I measured where the ST100 and ST130.
Just as a side note, another screen that was almost perfect was the Carada Bright White material. It measured 1.1 gain (it is rated at 1.4 gain). This was the most accurate and uniform of all the screen materials. The frame was high quality and it was easy to mount.
Originally Posted by G-Rex
All good info, but it seems from the posts the 1000 may not sufficiently light up a 141"x60" scope screen for 2d and 3d in a dark theater. Taking into account zooming and bulb aging...if the answer is no, or if it's even borderline then best to go with ST130. I am a bit hesitant to go with the 150. It depends on who you talk to, recommended gains have varied greatly (from .9 all the way to 1.7) for the 1000 on a large screen. My room is not ready for 6 weeks so I do not have to make a quick decision.