Debris in image after scanning

Hello, and I hope someone can offer help.

I've been using the Minolta Dimage III scanner for my 35mm slides and

have noticed a significant amount of debris on the image, after

scanning, when I zoom in on Photoshop. I resolved that it is not the

lens or camera box as I scanned the identical slide in the office

scanner with crystal clear results. My question: What would be

causing this? Is there a resolution? The Dimage III uses a plastic

holding device that tracks in and out of the scanner as it scans. I

also blow air and have used slide cleaning solutions to try and

resolve this issue.

Thanks, Ron Cordek

All film will have some dust and/or scratches. Some can be virtually clean. New, carelessly handled film can be worse than old, pristine film. Loose dust can be reduced by hurricane blower or similar, but stuck dust, and scratches, is gonna get scanned.

You can get a new scanner with ICE or Fare, which use infrared light to determine what is part of the emulsion and what is dust and scratches. Such scanners do not currently work with silver based black and white, and only marginally with Kodachrome. With your present scanner, I believe there is a software dust removal, but that it is not really that effective.

My regimen, for what it's worth, with Scan Dual II:

1. Prior to scan, use air blowing regimen (but no liquid cleaning solutions), handle the film as little and as carefully as possible. Try switching labs, if someone is consistently damaging your film.

2. Acquire Vuescan, initially only output raw files, and clean these, in Photoshop. These are the source files for producing finished images with Vuescan. Once you have these cleaned, you can experiment with different settings of brightness, film profile and clipping, without having to rehandle the film, or RECLEAN THE SCAN.

These files are very dark, but by setting up special proof viewing mode in Photoshop, you can raise the brightness sufficient to see into the deepest shadows, just. You are not changing the histogram, just the appearance. For brighter areas, I toggle back to rgb mode "ctrl" "y", for better feedback. For the extreme darkest area, you temporarily crank monitor brightness up to full.

In Photoshop I use healing brush, clone stamp and history brush sourced to Dust and Scratch treated snapshot. I usually view one frame at a time, at 100% minimum (w/ 2820 dpi Scan Dual II scans), going around the file.For tutorial on using the history brush, see:

http://www.computer-darkroom.com/tutorials/tutorial_5_1.htm

With above tutorial, I use one modification. I take two snapshots, one after dust and scratch treatment, and a second after adding noise. The reason being, with these very dark raw files, in the deeper shadows, the noise treatment becomes very blotchy. I will source mostly from the first snapshot, and only use the second snapshot in the brighter areas. The history brush used thus is a god-send for small isolated dust motes, particularly on variety of backgrounds.

For scratches across patterns, I've found non-aligned clone stamp is the last resort. You have to zoom in, and take your time. Try something, if it backfires, back up and try again. It WILL take time and patience, for scratches through chain-link fence, clothing patterns and the like. If you are very careful with your alignment, you can get the healing brush to behave very much like the clone stamp, except it blends in, virtually seamlessly, IF your alignment was spot-on. Try to source from equal or slightly darker tones, for best result. If you've got scratches across something random like grass or gravel, clone stamp works better. Just vary your source, and do short strokes.

After cleaning the raw file, I save it, open Vuescan, scan from this raw, with my default settings, and view the results in ACDSee. If I see additional cleaning is needed, I toggle back to Photoshop, clean, resave, rescan, review.

I will average 1/2 hour per image. Clean images, 10-15 minutes, with a significant portion of the time due to the overhead of opening and prepping images. Very dusty and/or scratches images will take hours...