Brightness: Again, we run up against the Sony's limited brightness as a deal breaker for those wanting larger screens. The Epsons are light canons in their brightest mode (Dynamic) pushing out a measured 1566 lumens, a pair of the brightest 1080p projectors around. That makes them almost 2.5 times brighter in best mode, a really dramatic difference.
Things aren't quite as bad for the Sony in "best" mode, where the Epsons mere 491 measured lumens are still over 1/3 brighter. Put this way, for movie viewing, the Epson will be as bright on a 116 inch diagonal screen as the Sony on a 100 inch screen.
Sharpness is similar. Lamp life should favor the Epsons whose 3000 hour lamp life at full power, and 4000 in low, should easily trump the VW70, which doesn't provide a lamp life claim, so we assume it to be about 2000 hours in high lamp power, and 2500 to 3000 in low. That translates into a lower cost of ownership for the Epsons.
The Epsons offer an array of frame interpolation, including creative frame interpolation for both 24fps (to 96fps) and 60 to 120, it also offers 5:5 frame interpolation (non-creative) taking 24fps to 120fps. The Sony, by comparison only takes 24fps to 48fps, (2:2), no creative. If you are into a lot of sports, or want smoother panning on your 24fps blu-ray movies, you probably will like Epson's interpolation schemes, however I don't think it's a big consideration for most people.
Ultimately, the Sony will provide a more refined image - that a purist will appreciate, and with it, slightly better black levels and shadow detail. The Epson's will have more horsepower, and more "pop and wow" factor. The Epsons, therefore, might be more fun to watch, but the Sony, overall, more technically correct. It's a lot of money difference, so much depends of your decision may be based on how much fanatacism you have vs. a limited budget.
VPL-VW70 vs. InFocus IN83
Ah, here we have two very different competitors. I'm a huge fan of the IN83's superb color accuracy. Its still got the best skin tones of any projector I've worked with in the last year. The Sony comes very close, but I have to give the advantage to the InFocus IN83 projector.
Black levels performance, though, is the IN83's weakness. Although not bad, the IN83's Darkchip4 DLP processor, without a dynamic iris cannot begin to match the Sony VW70. Of course, though, the IN83 does not compress the dynamic range of dark scenes like the Sony does. Both have excellent shadow detail, not enough difference for us to concern ourselves with.
Sharpness would be another strength of the IN83. Like the BenQ just covered above, and like most DLP projectors, it is exceptionally sharp. As I have stated many times, I don't have a problem with the Sony's sharpness, but some will really appreciate the extra crispness of the InFocus's image.
Click to enlarge. SO close
Placement flexibility is all Sony. The IN83 lacks lens shift and has a limiting 1.2:1 zoom lens, making it strictly a ceiling mountable projector, not suitable for rear shelf mounting. Both support an anamporphic lens.
And finally, brightness again, becomes a very defining difference between these two projectors. The InFocus IN83, afterall, is very bright, something the VW70 will never be accused of. In best mode, it's not even remotely a contest, with the Sony's 366 measured lumens paling by comparison to the IN83's 787 lumens. The difference is further magnified when you need maximum lumens. The Sony again has less than half the lumens, with just 636 lumens in dynamic mode, compared to the IN83's 1382 lumens! One thing I can tell you, the IN83 is a pleasure to watch sports on, filling all of my 128 inch screen even with moderate ambient light, that would drown the Sony.
Click Image to Enlarge
I'm generally torn between these two projectors. I'm a huge fan of using medium to larger screens, and of having lots of lumens for sports viewing with ambient light, but I'm also a black level performance fanatic. As a result, choosing between these two rather different projectors, to me, is pretty much a tie. It just comes down to which one is is better at the things you value most.