purple blotches on used 50/1.4

greenspun.com : LUSENET : Canon FD : One Thread

I just got my A1 CLA'd and am excited to start using again after several years of only using my EOS A2E. Instead of my snapshot oriented 28-70, I want a 50mm 1.4 SSC. I found one for a reasonable price on ebay, but had the following exchange with the seller. My question is, should I be worried about the condition?

Question: > I am interested in bidding on your lens. One questions is the condition of > the glass. When you look through the lens, from back to front, do you see > an marks or faint lines on any of the glass surfaces? > Answer:

A very good question... looking at an angle, there are two tiny purplish blotches on the outer edge of the lens that is closest to the camera. Looking through the lens like you describe, it looks like one of them causes a faint mark.

The lens that is farthest from the camera has always had a UV filter and is spotless.

Are these blotches are significant? If so, _please_ reply, so I can warn the other bidders.

-- philip emmanuele (philip@ecampus.com), June 29, 2000


Generally things like this are more cosmetic and affect the value of the lens more than the image that it produces. I think what the lens has is a bit of oil that's changing the apparent color of the AR coating. If so, it could probably come off quite easily in half and half ammonia plus hydrogen peroxide. Even if they didn't come off because they are at the outer edge of an element they would contribute only very slightly to image degradation. Consider for a second how rough a softening filter has to be to get the softening effect.

I was given an SSC 50/1.4 that got wet. The coatings of the outer elements had marks over about 30% of their areas. It made fine images even before cleaning up.

-- Duane K (dkucheran@creo.com), June 29, 2000.

Typically things on the rear element are more of a concern than on the front element. They have more effect on the picture quality.

It may be oil as the other post mentions, it may be something worse. It is impossible to say without seeing it in person. I would pass on the lens. As to warning other bidders, the seller might get a little upset at you. And since you don't know for sure whether this is really a problem, you may be guilty of slander or libel.

-- Terry Carraway (TCarraway@compuserve.com), July 02, 2000.

Moderation questions? read the FAQ