Copying photographic prints

BillJolly wrote:

Klarno and Guy Parsons have both suggested that you not try to copy color negs with your camera. I copied my old slides, color negs and bw negs with my GH2 and 50mm lens. The process for color negatives is a little different, but simple. In short, I did a custom white balance on a blank negative first. Then just copy the neg as usual, use the 'negative' operator in any graphics program and adjust the levels ( because the results are usually quite thin ). My results look fine to me. Hope you have good results.

Perhaps I should clarify the reasons why photographing color negatives is less than ideal-- with dedicated flatbed scanners you're getting 16 bit output (65,536 levels per channel), as opposed to 12 bit RAW on your camera (4096 levels per channel is the best the vast majority of cameras can bring to bear). This means that you have that much more leeway to work with things like the orange mask on color negative film-- you'll notice the 12 bit image getting pulled apart at the seams a lot faster than you'll notice the same thing happening to the 16 bit image. Some cameras offer 14 bit (16,384 levels per channel), but such things haven't worked their way into MFT yet.

The orange mask isn't a constant density filter; it actually forms in the development process in proportion to the other color dyes (it's there to correct for the inherent blue sensitivity of all color emulsions in color process papers). So I've actually found it to be nearly impossible to get accurate colors out of using a blank negative or film leader as a calibration step. You can get close, but I've found not close enough.

Your best bet to copy negatives with a camera is to use a dichroic enlarger head as your light source; a dichroic head is a special kind of enlarger that's used for optically printing color negative film. With that kind of head you can actually adjust the color balance of the light source quite precisely, which would make a great difference in getting more information in your images, leading to less noise and finer tonal gradations. You still need to boost contrast a lot though, because dye-based C41 films lead to very, very thin images.