I have often read comments in forums such as photo.net to the effect that scanning at numbers close 4000 ppi extracts all the image detail available in a 35mm image. I have long been skeptical of such comments. Here is a link to a scanner test that shows that scanning at higher numbers actually does extract more image detail. http://www.filmscanner.info/en/HasselbladFlextightX5.html The authors of the test compared results from a high end Nikon Super Coolscan 9000 ED scanner with an even higher end Hasselblad Flextight X5 scanner. The Nikon has a nominal resolution of 4000 ppi with an actual resolution of 3900 ppi, and the Hasselblad had a nominal resolution of 8000 ppi with an actual resolution of between 6150 and 6900 ppi, depending on the film orientation. The test scans showed that the 6000+ bit scanner clearly provided more image detail than the 3900 bit scanner, and it wasn't just the ability to resolve grain, but actual image detail. It was not even a case of the two being so closely matched as to require careful comparison. The difference was clearly seen by casual observation of blowups of a small part of an architectural image.