So I just went back to flatbed scanning after doing DSLR scanning this last year. A project I’m on isn’t giving the right results for my medium format work. I’m scanning in 6x7 negs with an Epson v600.
After scanning in a few test negs at 48bit RGB DNG 3200 DPI in a 4x6 print size the files were coming out to 480ish megs per image. Wow that is way to big for my workflow and this project. I was hoping to keep each scan around 100 meg as there is a lot of rolls, which makes the turn around to the publisher easier. They will want the master scan.
What would you recommend?
I tried 24bit RGB but that was giving me 250 megs. I could work with that but I wasn’t expecting to be making such large files. With DSLR scanning I was producing about a Gigabyte per roll which was acceptable.
Is there a trick with the print size or DPI I should be using?
Hi there, welcome to the forum. You could take a look at this review of the V600:
He finds that the quoted maximum 6400 ppi scanning resolution for 35mm is greatly exaggerated, in real terms you get no more than 1560 ppi but you have to scan at 3200 ppi to get that, so the files are stil much bigger than they need to be. I imagine that the same will be true for 120. He was using a high quality USAF 1951 target but you could do your own test with a nice sharp original 6x7cms negative.
I’m not sure what you mean about the 6”x4” print size but I think you can forget about that and just concentrate on the 3200 ppi. If you scan a 6 x 7 cms (actually more like 5.6 x 6.7cms) negative at 3200 ppi then you should end up with a scan measuring around 8441 px x 7055 px. That is 60MP which equates to around a 172MB uncompressed for 24-bit or 344 MB for 48-bit RGB. I’m not sure why your DNG files are a bit larger, perhaps this is the 4th digital ICE channel?
Anyway I’m guessing that you won’t see a difference in real resolution if you instead scan at 1600 ppi and you’ll end up with files 1/4 the size.
Better ask what they really need. A 16 bit TIFF, or will 8 bit do? Or a 90% sRGB JPEG? Pixel dimensions? A 4x6 in print should be happy with 1200x1800 pixels and AdobeRGB.