Jim Colwell wrote:
No, not produce, but "heal". There are some lenses that have some elements made in a special glass that is slightly radioactive and these turn yellowish with age.Henri,
I'm not convinced that simple exposure to sun light or UV will produce the yellow tint. I've seen and taken many pics of lenses with sunlight on and through the lens, and have not seen the yellow cast; however, as someone once said that I'm not always right (I still think that they were mistaken), I asked the seller and he assured me that the lens is crystal clear with no yellowing. He figures the yellow cast is a reflection from the SMC. I suppose it was from a nearby bunch of bananas or a passing yellow VW.
Jim
www.jcolwell.ca
To "fix" them you let sun light pass through it for a while, and the yellowness will disappear.
It could also be a SMC reflection as these lenses with the radioactive glasses are scarce.
Read more here: http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=008UdG
/Henri
