Looking at the slide film under a lamp, innumerable small scratches appear. More scratches and dust detects a slide scanner. The better the scanner, the better the image errors are also covered. By default, each scanning service so is the “digital ICE technology one. Here is sampled before the actual scan of the slide film with an infrared beam. The infrared beam detects increases (dust) and scratches (wells). Then, at these points with the digital image color pixels repaired in the area. That works great, but not always.
Often older slides are enclosed in glass. Through the glass, the infrared beam is reflected and refracted, the unambiguous assignment of the defects is no longer possible. Dirt on the glass surface, for example, fingerprints are not detected because they are not in Scan focus. The fingerprint is imaged in the digital image clearly. Black and white slides and Kodachrome slides also make problems. In these films there are silver particles. The infrared beam interpreted these particles as dust grains, which would lead to mass .
What are the countermeasures? Glass mounted slides can be that doubles but most of the digitization costs. Files from black and white films can be processed with appropriate software, which in turn reduces the image quality. But it is also quite different when photographing with the dust and scratches shown does not arise. This technique can digitize slides and negatives are offered extremely cheap. It also goes very fast, each task in 1000 is ready to ship within 48 hours.