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Forum: Pentax SLR Lens Discussion
12-14-2012, 08:24 PM
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Maybe it is the monitor calibration on my laptop, but none of the above lenses look particularly yellowed.
Steve
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Forum: Pentax SLR Lens Discussion
12-08-2012, 07:59 PM
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Thanks for the link. I had never seen any example where individual non-cemented elements had been shown as colored and had been cleared by UV light. That being said...Yellowing, by itself, it is still not proof positive of radiation. It may instead, simply be an indication of inferior balsam used in assembly that as yellowed with age or perhaps even mildly tinted glass used in the original construction.
Steve
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Forum: Pentax SLR Lens Discussion
12-06-2012, 09:41 PM
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...though radiation is not the only possible cause. The yellow is due to chemical changes in the balsam cement that holds the multi-element groups together.
That being said, the list of radioactive lenses seems to be growing steadily as various lenses are tested. Here is a link to an image and lengthy discussion/listing of "hot" lenses.
Radioactive lenses -- group shot | Flickr - Photo Sharing!
Steve
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