TServo2049 said:
Could someone more knowledgeable in film projection (poita?) explain again why garbage mattes are not perceptible when a print is projected in a theater?
That's right, with an optical process, getting blacks to match is an absolute nightmare. It is much easier now to push the image and check that it matches perfectly.
The garbage mattes are visible in the cinema however, I remember schoolkids arguing about the TIE Fighter's green-shields and pondering how they worked.
Most people won't notice them though, they are pretty close to black, and there is a lot of motion and laser blasts and other stuff happening. In '77 these effects and action were so damn amazing, that glitches were simply not noticed, you were just too blown away.
It is another of those things that you see once they are pointed out, and they are hard to un-see.
They are faint in the cinema though, mainly because of generational losses in the print making process, grain and relatively (compared to televisions) dim picture all contribute to the mattes being less noticeable. A 35mm projector with clear leader in the gate, in a good cinema will punch out about 14 foot-lamberts, that is considered a nice bright vibrant image. An LCD TV can be up to 140 foot lamberts, or about 10 times as bright. Even an old CRT telly is over 20 foot-lamberts. This makes things like garbage mattes, mismatches on matte paintings etc. stand out more on a TV than at the cinema, and the reduced colour resolution for home video releases can also contribute to it. The blacks get crushed more, shifting them more away from the colour of the garbage matte making it stand out more.
So they are there in the cinema, some people noticed them (like me on the 15th or so viewing at the cinema in '77) but most people didn't unless they were pointed out.