What exactly is going on inside my35mm 2.8?

[mitch]

There seems to be some kind of wear or damage to an internal part of my 35mm 2.8. It looks kind of like paint loss, but if you look through the lens into a light source at the right angle you can actually see light shining through cracks. This only happens when the lens is wide open, and you have to hold it at such a severe angle that I don't think it will actually affect the image quality. I've only shot two rolls with this lens so far, and I haven't noticed anything wrong with the pictures I took with the lens wide open, but then again I've never shot with another copy of this lens so I'm not sure what to expect.

Is this normal wear and tear with these old Canon RF lenses? Other than that issue, the lens is actually in great shape with no internal dust or haze, just some oil on the aperture blades, and the glass is great. What would you guys value this lens at in its current condition?

 

[Mackinaw]

Not too sure I know what you mean by light "shining through cracks," and your picture really doesn't show anything, at least to me.

Are the cracks partially open aperture blades? Maybe you're seeing lens separation.

Jim B.

 

[mitch]

I'm talking about the gray spots on the black ring inside the lens. If you look through the lens towards a light source, at the right angle, you can also see cracks in that ring.

 

[Mackinaw]

The glass elements are usually placed inside their own blackened interior barrel that is then fitted inside the exterior lens barrel. The spots may be flecks of paint that have chipped off the interior barrel (not all that unusual). As for the cracks, you got me on that one.

Jim B.

 

[Rob-F]

I see the gray spots on the black ring, which I take to be the front retaining ring. That, and light shining through cracks in the ring, which I assume is plastic, suggests the plastic is deteriorating with age.

However, I also see a sort of crackle look inside the lens optics, together with a partial ring around the periphery f the elements. These things suggest (to me, at least) that a cemented group could be separating.

I would send it to Sherry (Golden Touch) or else John Van Stelten in Colorado, and see what one of them can do with it.

 

[Mablo]

It's called "Schneideritis". I wouldn't mind about it. My 50mm/1.8 looked much worse but had absolutely no effect on image quality.