Tech Works Corner

Tech Works Corner

Restoring Kodachrome

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My latest tech challenge is the restoration of physically damaged old Kodachrome slides. These date back to 1941 and were taken on Maui by my grandfather. Aside from preserving and sharing these images digitally, this is part of a personal project to "reconstruct" the old town of Kahului from the 1930's to 40's when my father was growing up and my grandfather had a gas station business there.

The slides in question still have pretty vivid color, but have physically degraded very badly. The substrate has warped and crinkled (as if one had balled up the film and crushed it). The image has spotting and discoloration areas, and has fine cracks visible, as in a dried up mud-flat. I also have a lot of 8mm film which has the same problem.

Here are some shots of just one of the slides, taken at various angles, showing the extent of damage. Some of the slides, including the one below, were mounted in cardboard, then sandwiched between two glass plates, and taped on the edges. I don't know if this was done after some damaged had been noticed, or if it was done soon after the photo was taken, but in any case it doesn't seem to have protected the slides any more than the ones which were just mounted in cardboard.

(Macro "scan" through slide)


While I have the scanning and digital image processing tools, my call for help here is for advice on restoring the physical slide. I could fix all the image problems digitally after scanning, but because the slides are warped, a flat, undistorted scan is not possible. If you have any advice as to how the slides can be processed (e.g. liquid or vapor immersion, heating or cooling, physical pressure...) let me know. I have a few slides that can be sacrificed to experimentation, but I need to be sure it will work for the important ones.