Canon Lens Experts - does this look like a problem??

[gdi]

I have an old Canon RF lens that shows some silvery pattern around the inside perimeter of the lens when viewed from the front in two rings. I can't tell if it is the edges if the elements or what. Has anyone seen this type of thing before? I am not that familiar with Canon RF so I'm not sure what it is or if it is normal.

I tried as best I could to take a picture, but it is more difficult than just looking at it! These areas go all around the inside of the lens.

thanks!

 

[peterm1]

I would not call myself an expert but this looks a bit like de-lamination of a cemented element group to me. I have made a bit of a search to find lens block diagrams for canon lenses (to see if any have cemented elements at or near the front) but so far no luck. Which lens is this? This info might help. It is possible that if only seen at an angle that the pattern is the edge of the element. I have seen some that are painted black on the edges to prevent reflections.

 

[gdi]

Thanks, this a 50mm 0.95 that has been converted to M mount. There is a block diagram on the Canon museum site.

I do have the opportunity to return it if its a problem. I paid a lot for it, so I don't want to send it off for work right away.

 

[gdi]

Thanks Fred,

The lens seems to be converted fairly well, it is a TV lens so it looks a little odd and the finish is probably marginal as you say. I got it from a pretty well respected dealer, and he has suggested, like you that "I shoot first, ask questions later"! But he claims it doesn't have separation.

If this frosting (good description) is separation, is it likely to cause problems in the future, even though it is not evident now?

I believe it may be hard to resell if I have to do so in the future, so I might send it back anyway...