Testing used lenses (Craigslist/Kijiji)

[shannon0813]

I know I read something like this somewhere - but my searches aren't hitting what I need.

I'm possibly purchasing a used Sigma 10-20mm on the weekend from a Kijiji seller (as some may know from my previous post, i've been watching prices on a Canon 10-22 or equivalent).

I'm not concerned about the Canon -vs- Sigma issue (that has already been discussed at length - and for my uses - the differences wouldn't be a deterrence for me).

So - when I meet up with the seller - I will have my T3 body with me - and I need to know what I should test to make sure I'm not getting a dud lense.

I know I should test the AF to see if it's sharp and that the motor isn't too loud.

I know I should test the zoom to see if it's clunky.

Is there anything else (besides obvious wear on the lense?)

Thanks so much everyone!

[PhotoRebel4]

I've purchased a couple used lenses and didn't really know what all to look at either. I haven't run into any problems with mine, but I am really interested in seeing what others have to say about this for my future used lens purchases (I know there will be more).

In fact, I think a thread about what to look for and test when buying used gear would make a great sticky.

[Doug Sundseth]

Look through the lens and check for cloudiness. That can be a sign of mold (which would be an immediate disqualifier for me).

Don't worry too much if you see a scratch or two on the front element. Those generally don't affect the image, though you might be able to use them to affect the price you pay.

[zona5101]

if the t3 has a depth of field preview, you can use that and visually check the aperture blades close down smoothly and completely and release with no sluggishness. If would be nice if you had a laptop or other large display available to check for sharpness on a screen bigger than the back of your camera...