Hey everyone Im having some trouble figuring out how to get the best quality scans out of my film. Im currently trying to get my photographs ready for putting together a website, however I feel that the current images that I have scanned aren't as sharp as they can be. Im using my schools EPSON V700 and scanning my 6x7 negatives at 72(?) DPI with a target size of 10x13 using the negative trays provided. But like I said they dont seem as sharp as they should be, or as sharp as my local photolab have scanned previous negatives that are 35MM. It puzzles me because those are extremely sharp. Any suggestions????? How do you guys scan your medium format film for web display?
Basically you need to multiply your original size (6cm) by your enlargement factor (1.67 if the web size is 10cm), then multiply that by the DPI of the output device (72 or 100 dpi for most displays). Since you have mixed measures here (centimeters for the negative, and inches for the DPI, convert. 6cm = 2.36 inches, 10cm = 3.93 inches.)
But, that's going to get you a low number, like 200 dpi. What you might want to do instead is scan closer to the upper limit, like 2400 DPI in the scanner, then reduce in post (eg, in Photoshop) to the final image size you desire. Postscript tends to have pretty good algorithms for scaling images, and they will get sharper naturally as you downsize them.
If your scanner's film holders are not tuned to the right height, you will need to either shim the existing holders to be at the right height, or get a holder from betterscanning.com. Typically Epson v700 images are soft using the OEM holders, because the holders don't hold the film in the exact sharpest plane of focus. betterscanning.com holders give you the ability to raise the negative to the correct height. Or you can put little shims under the OEM holder's feet to raise the holder as needed to get the film in sharp focus. It takes a lot of fiddling to get it right.
Scans usually need some sharpening when scanned with a flatbed. But if the film is properly focused, you won't need much sharpening.
By the way, the advantage to scanning at lower DPI levels is you will be less likely to over-enlarge grain. If you scan at high resolution and reduce in Photoshop, but see more grain than you expected, try scanning at lower resolution and not reducing in Photoshop. Let us know which works better for you, I'm curious.