Originally Posted by stanger89
I don't really get that, you're going to have "bars" regardless of what you do, "black bars" are just dead space. With CIH they're just on the side instead of the top bottom. With masking there's still dead space, it's just covered with velvet or something instead of absence of light on a white screen.
(I know you are aware of much of what follows, but for others looking at this thread as well...)
The black bars annoy people because - using a scope movie on a 16:9 display as an example - you can see the size of your screen, and note that there are two strips of black bars taking up useless space on your screen.
And on most displays, certainly pretty much every projector, those black bars are visibly not black so they don't just "disappear." If you use CIH for you scope movies, obviously you no longer have those black bars for scope; you've got a screen shape, the image fits your screen, no visible black bars.
Masking achieves the same thing. There are no more black bars; it's impossible to be conscious of them because they can't be seen at all, the image simply fits your screen with no visible black bars.
The other issue for unmasked black bars is the perception of contrast. For many (but not all) types of scenes masking can improve the perception of contrast. As you know our perception of contrast is affected by various
factors, one being the proportion of brightness to darkness on a screen. Projected black (on digital projectors) is not pitch black, it's visibly lighter to our eyes. So take a projected "black" on a screen, then start to introduce
some small bright areas on the screen. The black starts to appear blacker in contrast to the brighter areas. Increase the amount of bright object area on the screen proportionate to the black area, and the lack looks darker and darker. As we know, you can have a projector with pretty lame on/off contrast, but on a bright scene with a woman holding a black handbag, the black handbag can look really dark due to it's contrast against the brighter area of the image. But it's when you start increasing the amount of projected black on the screen relative to bright areas, that you give your eye a chance to start seeing it's not really black.
And that's one of the things you are doing when you have projected black bars on a screen (still using 2:35:1 images on a 16:9 screen as example). You've effectively increased the amount of projected black area in your entire image relative to the bright parts of the picture, so your eye picks up the lack of true black quicker and more often as scenes get darker. Masking those bars away increases the bright-to-black ratio of your screen image, increasing the sense of contrast.
A number of times I've opened up my masking just to check it out on a scope movie and, especially for somewhat mixed night scenes I'm just aghast at the difference. It's like my image washes out and I feel like I've just bought a cheaper projector. It's a big sigh of relief when the masks slide back in and the image takes on that "pop" and punch, and that professional edge. I don't think I've read of anyone with a masking system who hasn't had essentially the same experience, the image looking clearly nicer with the masking.
Of course you can do CIH where, with 16:9 content on your 2:35:1 screen you aren't projecting "light gray" black bars on the side, so the side bars can go darker (providing also you have a non-reflective enough room to allow this, or a dark gray screen etc). I can see the black bars getting less distracting that way. But it gets into personal perception territory even more. I've never seen any system that wouldn't benefit from masking.
I have a black pit for movie watching, surrounded in black velvet, and I still see obvious benefit in bringing my side masking in for my 16:9 content.
It's two separate questions really: 1. Whether there is visible benefit for masking away black bars and 2. how much any particular person cares about that benefit (and or cares about the black bars on their screen).
I wouldn't try to argue anyone out of "not caring." If it's something that doesn't bug you, hey that's great. You've saved money. But if someone is interested in further perfecting the presentation and appearance of their image, masking can provide such gains.