Quote:
Originally Posted by WillAdams
charleski --- you're assuming that no one will view anything other than photographs / pixel images on such screens.
Finer linescreens allow for finer details to show through --- stochastic screening will show (visible) improvements in image detail all the way out to the limits of output resolution (I've worked w/ imagesetters which would go as high as 3,600 dpi).
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Yes, but your imagesetter is producing monochrome halftone screens, and each of the halftone cells has to accommodate the dots for each of the separations with enough density to allow at least 256 perceived levels in each channel. Additionally, digital halftoning requires higher resolution because of the sampled nature of the output (it can print 1 pixel, or 2 pixels, but not 1.5 pixels).
For a halftone process, the resultant lpi is equal to the dpi of each individual screen divided by 16 (a 16x16 cell gives 256 levels), meaning your 3600dpi imagesetter is producing 225lpi. This is certainly pretty high, but reasonable for output that will be viewed critically and needs to hold up under close scrutiny.
You'd need a higher output to display something that people might peer at from a few inches away, but if you assume the viewing distance won't go below 1 foot then there's no point going over 180lpi.