How to test if a lens is functioning properly as it should?

[airfang]

as well as delivering the IQ it should?





I just received my 16-35 f/2.8L II, and I would like to test if there's anything wrong with the lens.


What are the suggested method/procedures?


I notice Bryan shoots at some ISO chart, right?





Appreciate any input!

[Ken Schwarz]

It's really hard to tell if your lens is perfect but you should be able to judge gross problems pretty quickly. I tested my lenses by photographing my computer LCD. I used Live View to accurately set center focus and then inspected the rest of the frame for sharpness. If you look closely, you can see the pixels of the screen clearly--that is the indication of good focus. It was very hard to be sure that the camera was square with the screen, which makes the test somewhat unreliable. I looked for asymmetries or other obvious problems and found none. Then I made sure that focus worked at different distances and that exposure was correct at different f-stops. That's pretty much it. Most lens problems are, I suspect, related to near/far focus adjustment issues. If you have a recent-vintage body, you can adjust this.

[Steve Eisenberg]

Download this focus test:


http://www.dphotojournal.com/download-free-focus-test-chart/

[Kyle Webb]

Airfang,


If your camera body has micro lens adjustment features then try performing a micro lens adjustment on your new lens. Doing so will tell a lot about the lens perfromance.


Kyle

[airfang]

Thx all for the suggestions! But unfortunately, my camera (Canon 30D) has neither Live View nor micro lens adjustment. I will give the focus test a try when I have time.


Anyway, I appreciate your inputs!

[Steve Eisenberg]

The focus test just takes a few minutes, and will tell you if you have back or front focus. Just be sure to tape it down, and use a tripod. It's probably just fine. Take a bunch of pictures, and if they look great to you, you're in good shape. And have fun!!