"Sigma SD1 Merrill not good for scanning negatives/slides"

JohnK wrote:

Hey Dr Tebi, I’m confused, so is it good or not good? It says not good, but the sample pics look alright. What about the QH? I was going to use it to scan some slides I made in the 70’s but don’t want to waste my time if Sigmas are no good for this. Should I use my other camera instead? I’m going to use a tripod and a lightbox, how do you think that would work? Will the files be good enough to print at 12x18?

What film were you using and how dirty are the slides? And how many slides is "some"?

Answers to this will determine whether a camera scan is appropriate. The issue with a real scanner is threefold. First, it will usually have higher dmax values. Second, it will have an infrared channel to clean out dust and scratches, and third, it will have some way to calibrate the film color. Many slides will come out bluish or purple when in fact the color is ok on the slide. Some slides have color fading which can be fixed by the software if it isn't too severe. Resolution. Some slides have 10-15 effective MP, others can have up to 140mp in 35mm*. It depends on which equipment and how carefully it was taken. You know what equipment you used. The sigma won't get all the detail in the higher-end images. No scan will be as sharp as the projected slide, however.

* https://www.anatomyfilms.com/kodachrome-king-dead/

Fixing all these things on your own with a camera is time-consuming, especially for older slides. I recommend remounting the slides and cleaning them first in a chemical solution made for film. Do it outside. The smell is strong.