Should make Unsharp Mask on when scanning

Discussion in 'Digital Darkroom' started by pankaj purohit, Jun 27, 2008.

  1. Hi, Now days I am working on scanning 35 mm negative films. I recently bought a canon 8800f flatbed scanner (Please don't tell me to have a dedicated scanner). I realy found that it is working so well with the films. But one thing made me confused with the scanning, that is :: should I always scan the 35mm negatives with unsharp mask on whether it prodeuces great sharp image with lot of details (Offcourse the noise/grain increases in this case) but I found, some are in far (DOF smoothness) also becomes sharp, while scanning without unsharp mask then DOF comes out greatly and no much noise is there, but focused ares also lake sharp details and contrasty sharpness. One more thing I would say here that, if I apply various sharpnings in photoshop, that does't work so well as the scanner's sharpness. Please share your thoughts... Thanks
  2. when scanning with a flatbed that have a glass between the film and the lens, i suggest people apply a ligth to medium sharpen to remove the softness cause by the glass. I also suggest you apply another control sharpness later in Photoshop; better control, easier to play with the opacity and can be apply to certain area only.
  3. I always scan with unsharp mask on medium in Epson Scan. Then sharpen to taste in my editor on the full resolution image in post processing after other edits are finished. Noise reduction depends on the image.
  4. Thanks Patrick and Sam for your replies,

    Patrick, unfortunately, I dont have various settings for unsharp mas, it only has on or off....

    Scanning with the unsharp mask, reduces effects of DOF, so thats is the issue, if see images upper, you can feel it.

    Thanks again...
  5. Bottom crops of pipe on the floor is the background far, so DOF should be like "Nosharp" one..

    Sorry I forgot to mention the DOF part on image...
  6. poor you! leave it on than, or get a better scanner like a epson ; )
  7. Global sharpening will exaggerate grain and is to be avoided when scanning film. This is CRITICAL in achieving the best signal/noise ratio in film scans. Admittedly, your flatbed will not capture as much grain as a more targeted scanner would, but you'll still see the problem. If your scanner software offers no sharpening adjustments, then all the more reason to scrupulously avoid it. One size does NOT fit all when it comes to sharpening.

    The reason you see less apparent DOF in your sharpened scans is because you're bringing up the background noise level with global sharpening. This makes everything appear to be on the same plane and ruins the illusion of depth.

    Scan with no sharpening, and then use any competent selective edge sharpening routine (either home-brew or commercial) as part of your post-processing workflow and you'll find you'll get better results with far less need for subsequent detail-killing noise reduction.

  8. I don't scan much anymore, but my general philosophy is to only apply modifications at image-acquisition time (i.e. scanning) that cannot be applied equally well to the "untouched" image. That way if you decide there's a better filter you can go back to the original and do things differently.

    One example of processing that (so far as I know) can't be done post-scan is ICE, since that requires a second IR scan of the slide/negative.
  9. Thanks Again buddies...!

    Scot, you are right that globaly sharp scan would bring more noises and I do agree with you and I have experienced it.

    But as said earlier (as my experience) that sharpening in phtoshop onle makes good sharp image and we can be selective to sharp or not to sharp, but I felt that, if I scan with unsharp mask seetings on, than image comes with more details and with more dynamic range.(if you have noticed the images posted upper, the image might be more grainy/noisy because it is a 200 ISO 35mm film, and I am to test the 100 ISOs next with this scanner, earlier I have done lot of 100 ISO scannongs with canon 4400f).

    So these are the areas to conern about....

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