Why does the aperture on this lens close so slowly?

[Ett]

Hey guys

A buddy of mine gave me her Nikkor 105mm 2.8G Macro lens to play with. I took some shots and found that the depth of field was WAY too shallow. But when I stopped the lens down, it didn't change at all. In fact, light didn't change either. I stopped down from 3.5 all the way to f22 - DoF was the same, light was the same. So I had a look, and it seems that the aperture blades take some time to close. When I do a long exposure, it takes the aperture blades about 1/10 or 1/8 to close down, which means that in a 1/1000 exposure, I'll basically see f/3.5 no matter what I set it to.

I assume that there's something wrong with this lens, but I just want to check with you guys first. I've never played around with macro lenses, so maybe it's something I don't know, but as far as it looks, it looks like this lens has a problem.

Thanks

[sk66]

Sticky aperture blades. It's a problem with the lens.

[PhotoRebel4]

Regardless of the aperture blade problem, it IS a macro lens and therefore is going to give you a very shallow DOF due to the design itself.