Roger Krueger writes: >>>>>>>>>> Comparing digicam pixels to scanner pixels is misleading because scanner pixels are second-generation--4000 scanner pixels=2700 digicam pixels seems empirically like a good approximation, but I don't have research to prove this. <<<<<<<<<<<
My estimate is 4000 scanner pixels=2400 digicam pixels. Here's a scan (the left is an in focus scan and the right an out of focus scan of the same area) first straight, and then carefully downsampled to 2400 dpi. (Velvia 100F) http://www.pbase.com/image/22348855/original http://www.pbase.com/image/22348935/original >>>>>>>>>> And comparing lines resolved between digicams and film is a little misleading anyway--digicam generally have pretty decent MTF right down to their theoretical limit, then fall off to zero. On film, the MTF starts to fall off sooner, but keeps going longer. Assuming 3 pixels/line pair, 300 dpi can resolve a hair under 4 lp/mm. 200 dpi is 2.6 lp/mm. Both well under the "standards" for a fine enlarger print of 6-8 lp/mm. The catch is that at the 3 lp/mm frequency, the 300 dpi digital probably has better MTF than the enlarger print, even though it loses the ultimate resolution battle. The reason you "need" 6-8 lp/mm from an enlarger print is not so much that you can actually see that resolution from a normal viewing distance, but that a 10% MTF at 6 lp/mm is a good predictor of a 80%+ MTF at 2-3 lp/mm, which is what really matters. <<<<<<<<<<<< Agreed. This is, IMHO, exactly right. David J. Littleboy Tokyo, Japan ---------------------------------------------------------------------------------------- Unsubscribe by mail to [EMAIL PROTECTED], with 'unsubscribe filmscanners' or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or body