Slides and negatives always have small dust particles and tiny scratches on them, even when handled very carefully. Removing them one-by-one takes a tremendous amount of time, since often hundreds or thousands of small defects (dust grains or lint) are found on the original image, which only become visible after digitization. LaserSoft Imaging has developed a reliable solution to this problem.
Infrared light has a very wide wave-length, which allows it to pass through film emulsion of negatives and slides without resistance, as opposed to scratches and dust particles that reflect it. iSRD utilizes this behavior as follows. The image is scanned two times – the first is the regular RGB scan and the second is the additional infrared scan that captures defects like dust and scratches only. Then the calculative dust and scratch removal takes effect, only where the infrared channel has detected any defects without losing any important details.