Recently I gave some of my old dias (24x36mm and 6x9cm) to a professional scanning service that has good references. The scans were made with an up-to-date Nikon scanner at 4000 dpi and saved in maximum quality JPG (12).
DT refused most of these scans and told me, that there were distorted pixels. As I looked more closely at the images I found that DT was right and the question emerged what to do against this loss of quality. Do you have some tips for me?
PS: I do not own Photoshop, but Photoshop Elements, and I am not an expert in digital image manipulation.