Archived posting to the Leica Users Group, 2001/01/09
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]on 9/1/01 7:55 am, Dante A. Stella at dante@umich.edu wrote: > As far as I can tell, T400CN has 15 stops of contrast. I thought that > translated into more bits (since it's about 1 bit per zone). At any rate, > it should be scanned in 16-bit color and then squashed into one color > channel, but that was not practical, given the color corrections and > ultimate file size target. Maybe there is a better way to express this. > T400 has no shoulder for about 15 stops. I think you have the wrong end of the stick here, Dante. You can scan contrasty negs at 8 bits just fine. It's all down to the scanner's Dmax. The scanner MAPS the neg contrast into 8 or 12 or 14 or 16 bits. The number of bits doesn't tell you where the scanner gives up on a dense neg... that's what the Dmax tells you. Otherwise a 16-bit scan from a Dmax 3.0 scanner would capture a greater dynamic range than an 8-bit scan from a Dmax 3.4 scanner, which is not the case. The extra bits give you finer gradations between Dmin and Dmax, not a greater Dmax. The blown highlights on the models nose are either a sign that the density of the negative is greater than your scanner's Dmax, or that the white point is clipped (most likely, as most scanner software deliberately does this). - -- Johnny Deadman http://www.pinkheadedbug.com