samirkharusi
Nov 22 2002, 08:05 AM
The D30, crop factor or not, is fairly easy, IMHO. There are not enough pixels for huge prints, so presumably the question should not be addressed from the size-of-print you are looking for (normal approach), but what is the smallest circle of confusion that the pixels can resolve. The pixels in a D30 are 9.5x9.5 microns, so, IMHO, it would be quite pointless to use a circle of confusion with a diameter smaller than 9.5 microns = 0.0095mm. The usual approach starts from the print size (usually taken as 8x10" or 8x12" = 8x magnification of an uncropped 35mm full format frame). Normal vision resolves around 5 line-pairs/mm or 0.1mm COC in the print = 0.0125mm on film. With the 1.6 crop factor this would translate to 12.8x magnification (instead of 8x) or 0.008mm in a D30 or a D60. As per earlier statement it would be useless to go below 0.0095 in a D30, but OK to use 0.008 in a D60 (which has 7.5 micron pixels = 0.0075mm). Hope this helps.