dave@onfcanim.UUCP (Dave Martindale) (09/14/86)
In article <7117@utzoo.UUCP> henry@utzoo.UUCP (Henry Spencer) writes: >> ... But you're going to need a *lot* more resolution for output... >> You need a minimum of 2K resolution, anti-aliased >> for good looking slides. TV requirements are way lower, about 656 x 485 >> for NTSC encoded RGB. For retouching photos for prepress, you're going >> to need 1000 dots per inch... > >It should be mentioned that there is a tradeoff here: better anti-aliasing >can give satisfactory results with lower resolution. Many of the people >doing movie animation will tell you that, say, 2K resolution is vital. >The computer graphics group at Lucasfilm consistently produces high-quality >images using only TV resolution, by doing *good* anti-aliasing. Likewise >for the people at NYIT. In animation, you should *always* do good anti-aliasing, since the artifacts otherwise produced - small features that appear and disappear, "jaggies" that crawl along an edge, etc. - are a lot more noticeable on (slowly) moving objects than in still images. Once you've accepted that you need to do good anti-aliasing, then the output resolution that you choose determines how much detail will be visible in the final result. A fairly low output resolution, combined with proper anti-aliasing, produces just about the same effect as an infinite-resolution image somewhat out of focus. Now, 2K resolution for 35mm cine frames is probably higher resolution than the film is capable of reproducing, at least with any amount of contrast. In this case, the film itself (and perhaps the film recorder's lens) will be doing some anti-aliasing of its own by blurring pixels together. Think of this as ordinary over-sampling with the filtering done optically. For some people's applications, this may be cheaper than doing the filtering digitally. However, 2K resolution for 35mm slides (twice the area of cine frames) recorded on slow transparency film may be quite reasonable, particularly if the slide includes text, not just pictures.