Oh boy! Nothing like a challenge. Five hundred lumens and change to start with doesn't leave you with much by the time you separate out the two signals - one to each eye, and have each eye's shutter closed for more than half the time. The bottom line is a loss of 75% brightness or more. 125 lumens doesn't buy you much, and in reality, it's going to be lower.
Since the JVC DLA-RS60 was here, two new screens arrived. One is the Studiotek 130 and the other, also a Stewart screen is their Silver 3D screen. I've been watching the Sony VPL-VW90ES on those two, and my Carada. The Studiotek and the Carada are fairly similar, but the Silver 3D screen really makes a difference. The JVC by our measurements, is only 2/3rds as bright as the Sony, and it needs even more help, to not be DIM. The Silver 3D is much brighter - but mostly in the reflective sweet spot. If you are sitting dead center, then it's not hard to see significant roll-off of brightness by the sides and corners, but, remember. the eye is drawn to the brighter areas. So, the roll-off isn't always obvious, but it's there and significant. If you are sitting to one side, the far corners will be significantly dimmer than the screen closest to you.
By comparison, with the Sony, filling the 100" diagonal 16:9 3D screen actually produced an image that was not overtly dim. In fact, in the center areas on bright scenes, it looked reasonably bright.
I might be able to "survive" fairly well for a year with the 3D's brightness with the Silver 3D screen, if using the Sony, or even the JVC, with a fairly new lamp. With the JVC's lower brightness, unless we can get a watchable picture with the color profile off, when we retest, the JVC on a 100" diagonal typical screen, will have about the same brightness (with a new lamp) as is specified as the mininum in 3D theaters.
Remember I've always more concerned with brightness than many other reviewers, but, keep in mind that the movie theater standards call for 16 ft-lambert's brightness with a minimum of 12 ft-lamberts for 2D. The recommended number for 3D, though, is much lower still, with the SMPTE minimum standard for 3D in theaters, of 4.5 ft-lamberts The JVC can achieve that 4.5 ft-lamberts with a new lamp, on a good white surfaced screen around 90 inches (larger with higher gain) SMPTE: Society of Motion Picture and Television Engineers. The question is, is the standard bright enough?
That's not much more than 1/3 the brightness. of the 2D standard. Mind you it's been pointed out, that due to the nature of 3D, a lot of the issues, artifacts etc. are far less noticeable when the image isn't as bright. Note, that's also true for those of us sensitive to the rainbow effect. The brighter the image, the more likely someone rainbow sensitive like me, will notice the rainbows. The argument can be made, therefore, that while the image lacks in brightness, you are less likely to notice some pesky artifacts. That's a good story, and has some validity. Still, the solution is a brighter image, and the artifacts issues removed by improvements in technology, rather than hiding flaws by reducing brightness.
With that 100" screen (1.0 gain) the JVC, figuring 550 lumens would only be about 18 ft-lamberts with a brand new lamp in 2D. Since at most only 25% gets to your eyes, that's going to be no more than 4.5 ft-lamberts on day one, and less by the time you have a few hundred hours on the lamp. And that's with best positioning (wide-angle on the zoom). Going with a moderate gain screen will help, say 1.3-1.5 but for a dramatic difference in brightness, one needed, a hi-power screen may be called for.
The incoming Da-lite High Power screen should be brighter still and we'll report on that when it arrives and is mounted.
The trick to making screens work for you, I think, in this case, is to have two different ones. I've set up my room with a 100" Silver 3D (16:9) fixed wall, and my new 124" Studiotek 130 2.35" is motorized and comes down for my old fashioned 2D viewing.
Not a perfect solution, but consider two screens as one way to get the job done, with todays somewhat dim 3D projectors for the home, and without compromising the best possible picture from what may well be the best under $15,000 2D 1080p projector.