rehess wrote:
Before I was willing to retire my film camera, I did an experiment which convinced me that a 6mp digital image would contain all the detail in a Kodachrome 25 slide.
selmslie wrote:
That is a difficult comparison to make unless you use a very detailed Kodachrome slide scanned with a good scanner.
My testing was as follows:
(1) I selected some Kodachrome 25 slides which had identifiable detail on them, such as reading material, railroad equipment with small lettering, rivets, weld lines, and other things that might matter to me. I tried to pick slides which I had felt all long did not capture the sharpness available in the original situation, meaning that this rendition was the best Kodachrome 25 was going to do (*)
(2) I sent the slides to a professional, who scanned them and returned them with a CD of 3000 x 2000 JPEG images
(3) I set my projector up next to our computer, and put the screen across the room
(4) For each slide, I looked for every identifiable detail.
In every case, I was able to find every identifiable detail from the slide on the image. For years I stated my conclusion as "at the level I'm willing to pay for, a 6mp image has as much detail as I was getting from Kodachrome 25", and I kind of wondered how the 50mm f/1.7 lens kitted with my Pentax Super Program {the system used to take most of those slides} had affected my results.
Last year, I switched back away from Canon Rebel cameras, and got myself a Pentax K-30. For the first time in twenty years I was able to use that Pentax-A 50mm f/1.7 lens - for the first time ever on a digital system - so, of course, I did so. I was shocked, and thrilled, when the results were at least as sharp as what I was getting with my more modern Pentax lenses, and sharper than anything I had ever gotten with Kodachrome 25; thus, I concluded that lens had never been the weak spot in my system. I am sure medium format would have given me more sharpness, but I doubt if
any 35mm system would have delivered more sharpness than I am getting with my entry-level Pentax DSLR camera today.
(*) Yes, I know that there is always focus accuracy to deal with. However, because of my interest in context, my natural inclination has always been to use f-stops around f/8 {or even f/11 with film}, so I am quite confident that focusing did not cause the minor issues I was aware of.
added: I own an elderly Nikon LS-2000 scanner. It seems to do a reasonable job of catching what is on my slides.