Infrared Dust Removal Is Confused by Kodachrome Slides
Recorded on November 6th, 2016
I learned tonight that infrared doesn’t pass (or doesn’t pass easily) through the silver halide in Kodachrome slide film. This hampers the effectiveness of IR-based dust & scratch removal like SilverFast uses. It starts seeing dark parts of the image as deep scratches that need to be removed. It’s still somewhat effective, and as long as you don’t crank it up too much you won’t get terrible false-alarm artifacts.
Thankfully, SilverFast has a parallel purely software-based dust & scratch filter that does a pretty good job in tandem with the IR-based filter. I’m still experimenting, but I think I’ve found a good middle ground: