Originally posted by jsherman999 How would you get rid of yellowing on an old SMC takumar? Do you need to take it apart and clean it with some solution? I thought I'd read that you can get id of the yellowing by exposing it to light, or something, but I can't find where I read that now....
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Hello, jsherman999!
I resolved a pretty bad yellowing case of my SMC Tak 2/35mm last week. When I bought it the vendor didn't told me about this and in the test photos I mistake the tint as a white balance problem
. I knew about the UV cure and a friend (electrical engineer) made for me a UV source (mercury lamp, about 80w of power, no UV filter). I put the lamp and the lens in a cardboard box (warning, this kind of UV is harmful for you - especially for the eyes!) and 15 hours latter (in 2 sessions) the lens was crystal clear. To be honest I saw the lens clearing from the first hours. The light is a tantalizing electric blue!
Specific condition: wrap the lens in alu foil (including between lens cap and front element), open to max aperture, distance about 2 inches (5 cm), rotate from time to time, cover the box with some fabric or alu foil to block uv and let the interior of the box cool. I got only minor warming of the lens but also a strong, bad odor in the room so keep it in a restricted area. When I'll get my K20D I will make for sure some test photos, and yes on my K100D the manual white balance trick worked pretty well.
Hope this helps you!
Radu