Originally Posted by Deja Vu
Brightness matching and screens (my take):
You brightness match two very good projectors compare them. Of the two projectors, projector B appears overall better to your eye -- a little better contrast, colour, and so on. So you decide to purchase projector B. A few weeks latter you visit a friend's place and he has projector A and you watch a movie and conclude that you actually like projector A better than projector B, which you now own. You now conclude that the extra brightness of projector A makes all the difference to you -- it overcomes the slightly better contrast, etc. of projector B and opens up the image and makes for a better viewing experience. Now you think, "why oh why did I handicap projector A when I compared the two". No matter what you do you can't increase the lumens of projector B (it is what it is) -- but wait, you go to the AVS forum and find a used HP 2.8 gain screen and buy it. Now projector B produces a brighter image than projector A and you can even watch some 3D. Your friend with projector A sees your image and is now trying to figure out how he can obtain the image you now have!
Firstly, I don't know how a weeks later you'd have any clue if your friends projector, on a different screen, in a different theater is brighter/dimmer/whatever than yours. But regardless, I haven't seen anyone, ever say discount the brightness advantage, I think the "anti-brightness-matching" crowd is missunderstanding the intent and use-case for brightness matching. You don't "handicap" the brighter projector, you eliminate variables that contaminate the results. Consider this alternative scenario:
Say you're looking at two projectors, one is 50% brighter with 30% better contrast. Well if you don't brightness match you'll see that the dimmer projector has a better black level. Say the dimmer projector has "enough" brightness for your screen size/environment, so you pick that, for the better black level. Then you see the brighter projector dimmed down to your desired level end realize you were wrong, that it actually has a better black level (more contrast) than the one you bought. If you'd brightness matched them in the first place, you'd realize the brighter projector had significantly better contrast, and probably would have picked that.
You have to do both, you have to look at both brightness matched to understand how they handle color, contrast, grayscale, etc. But you also have to figure in brightness as well.
But maybe here's the biggest reason. If I'm reading someone's report on seeing two projectors and they weren't brightness matched, I have to throw out almost the entire review because I don't know what differences were due to the extra brightness (if seen in isolation are the colors actually better, or is it just an illusion due to brightness difference).
It's easy to adjust your expectations for brightness based on a brightness matched review, but you really can't do the reverse. What I'm saying is if you look at a brightness matched comparison that says projector x has better contrast
Originally Posted by beastaudio
Wow, was the image behind how bring you were previously watching movies? That seems incredibly dim to me....
This is a prime example of why you should brightness match. Yeah, that other screen looks dull, but that may
only be because of the relative difference between the two. I bet that other screen looks great if you don't have the HP skewing your perception.
Again, I'm not, and I don't think anyone is saying to ignore brightness differences, but brightness differences skew perception of every other image attribute
, so if you don't brightness match, the conclusions you draw for every other attribute, sharpness, contrast, colors, etc, are all suspect and can't be trusted.