How do I tell if the lens is good?

pjaye · Mar 17, 2014

I bought two used lens on the weekend. I see posts here talking about lens issues, and aberrations. How do I tell? One was a little pricey, the tamron 18-270, and one was super cheap Nikon 35-80. If the Tamron is not good, I can return it. but I can't return the Nikon. However, the Nikon was only $50, so not a huge loss. I took some pictures but haven't had a chance to really test them yet.

I only used the Tamron to test the boyfriends new NikonD50 and make sure it worked, and those pictures were taken out of the store window and a moving car.

I used the Nikon tonight, just indoors, with bounced flash and using my "not impressed" cat as my usual test subject. Those pictures look ok, maybe a little soft (I'm also getting used to a *much* heavier camera with a battery grip) and the colors aren't great, but again, I'm indoors, in the evening, with bounced flash and NO natural light.

What should I be looking for in the pictures to tell if the lens is ok? I can post pictures if anyone wants, but they really aren't great. I'm planning on a hike this weekend, providing the weather co-operates, and so will really get to test them then.

I'm also just a hobby photographer, not professional, so I don't need top of the line lenses.

runnah · Mar 17, 2014

9 times out of 10 any lens "issue" is due to user error. Some lenses are soft wide open or closed. This is normal. Try your lens out at around f8 and in good light. If you cannot get a sharp image you might have a issue.

pjaye · Mar 17, 2014

runnah said:
9 times out of 10 any lens "issue" is due to user error. Some lenses are soft wide open or closed. This is normal. Try your lens out at around f8 and in good light. If you cannot get a sharp image you might have a issue.

Thank you. That will be the plan for this weekend when I can get outside.

Braineack · Mar 17, 2014

Test against a known good lens in a controlled setting. Post results.

pjaye · Mar 17, 2014

Braineack said:
Test against a known good lens in a controlled setting. Post results.

Ok, and why didn't I think of that? Sorry, it's been a long day. So here's a stupid question, should I be comparing my new lens with a known good lens of roughly the same focal length? Or does it really not matter?