60mm macro: It's sharp and focus is great- but do I still need to send it back?

I've been using my 60mm macro for a little while. I love it. The photos are great. But when cleaning it in preparation for tomorrow's shoot, I noticed something that looked funny...

With the lens off the camera, the aperture blades don't seem fully retracted. So I checked my other lenses and as expected, you couldn't even see the blades.

Attached are two pics of the 60mm. One wide open, one stopped down to 5.6. It doesn't even look even to me... what do you think?

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And here is my 70-200 and the sigma 30 1.4

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And the 10-22. all perfectly circular.

I'm just wondering if there's some kind of a design difference with the 60mm that would make it behave like this... unlikely but I thought I'd ask before sending it to canon.

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I just looked at mine (off the camera, so it's wide open).

The iris is round at infinity but I see the diaphragm leaves just as you do with the lens focused closer.

Is yours round at infinity?

-js

BTW, at infinity I can see one of the iris leaves if I look into the lens off-axis.

-js

I'm looking at it straight in, the same way I was looking through all the other lenses. But no matter what angle I look at it, it's never round.

OK, I just put the 60 on my camera and peered into it. It's round, or very nearly so, wide open at infinity but at focusing distances of 5 feet or closer the iris leaves are very pronounced.

-js

The 60mm has 7 blades compared to the 70-200 which has 8 and the 10-22 has 6 blades, so could the blade count be the 'reason' for the differences you have noticed?

HTH

picturecrazy wrote in post #3583096
I'm looking at it straight in, the same way I was looking through all the other lenses. But no matter what angle I look at it, it's never round.

What focus distance do you have it set to? My guess is that the lens is fine.

Send it in. None of my lenses show the blades when wide open...be it my $8 Lentars or my $1600 70-200. If, for some reason, that's normal for that lens, Canon will tell you. If it's not they'll fix it.

pmc, the 60 has 7 leaves to the aperture and should have a neat circle at almost any setting, certainly it should be evenly opened. You might want to take it to a shop and have them look at it to determine if it should go to canon or not. Then again, if it's taking excellent pictures I wouldn't worry too much about it.

I've never seen this before, but I've never looked into a 1:1 macro lens before either.

-js

wannabegood wrote in post #3583159
pmc, the 60 has 7 leaves to the aperture and should have a neat circle at almost any setting, certainly it should be evenly opened. You might want to take it to a shop and have them look at it to determine if it should go to canon or not. Then again, if it's taking excellent pictures I wouldn't worry too much about it.

Ummm, I assume you mean that it should be a neat circle wide open. At any aperture other than f/2.8 it will be a septagon.

I wouldn't worry about it either.

-js

Sorry Lloyd, I saw "picture me crazy" when I saw your ID, must've been looking at myself in my own avitar a little too much!

I never noticed that in my 60, but alas I don't have it any more to check it! I miss it too! Maybe you or someone reading these can tell me if that EF-S lens will work on my 5D with an extension tube or an adapter??

If the pics are sharp and the af is quick, just carry on and keep it in mind, that's what I'd do. Enjoy it, they're hard to beat!

#6 is Septing out on us!