How to test a new lens?

Ok, I am a photo guy, not a gear guy (see my signature) and I recently bought a used 135l and just used it out the gate and I am happy as it rules from what I can tell(that lens is no joke and worth the hype). I also have had great experience with sigmas, although my 10-20 is a little softer in one corner, but for what it is it never bothered me as it is minor.

Anyway, that is my style, I don't shoot boxes, charts or cats out of the box. HOWEVER, I just plunked down for a 24 1.4 and I really, really want to verify it is a good copy because of the investment, rather than use it for a month and realize a corner is soft or something. Is there a simple way to run it through some paces to confirm it is as should be? If so, how? I was just going to mf shoot a brick wall or Similar at various apertures and then view 100%

Thanks

Nick3434 wrote in post #16499220
Ok, I am a photo guy, not a gear guy (see my signature) and I recently bought a used 135l and just used it out the gate and I am happy as it rules from what I can tell(that lens is no joke and worth the hype). I also have had great experience with sigmas, although my 10-20 is a little softer in one corner, but for what it is it never bothered me as it is minor.

Anyway, that is my style, I don't shoot boxes, charts or cats out of the box. HOWEVER, I just plunked down for a 24 1.4 and I really, really want to verify it is a good copy because of the investment, rather than use it for a month and realize a corner is soft or something. Is there a simple way to run it through some paces to confirm it is as should be? If so, how? I was just going to mf shoot a brick wall or Similar at various apertures and then view 100%

Thanks

The best way to test any photo equipment is to "use it for a month." Of course, you could always hire a testing lab, but that will still probably take the better part of a month and cost far more than just using the lens in the way you typically use it. Of course, if you're already convinced that you'll eventually find a flaw, you're dealing with a self-fulfilling fear that may have no solution.

When you get a new lens, go out and shoot at different distances, apertures, FL for zooms. 20-50 photos would cover even a zoom.

Get back home and take a closer look. Is there anything obviously wrong?

You are looking for 3 major things.

a) AF, front/back focus, consistency over aperture and distances. If it consistently front focuses for example, you can take care of that. If it is all over the place, then you can't (I had this happen to me).

b) Corner sharpness/overall sharpness. Shooting squarely a brick wall. And I MEAN SQUARELY. Use a tripod a level, a draftsman's triangle. You have problems if you can tell that the focus is spot on but the image is soft in general and you can't get it any sharper in Live View. If this happens with your EF 24L send it back to mama either for another copy or for Canon to adjust.

c) One side is sharper than the other, decentering. Same as b) The brick wall will suffice.

Another measurbator is born!

http://www.lensrentals​.com …010/11/how-to-test-a-lens

Thanks bearman! That is what I was looking for.

Yeah I know what to look for in pics but didn't know if there was a fast dirty way to just make sure it is on the up and up and then get to the enjoying part. Measurebater, not so much....I really am not bothered by things or look for them, but for this kind of money, I don't want to realize a corner is soft after a month with no recourse(al la my sigma, which is acceptable, but not acceptable for $1600). I think that is pretty reasonable.

I have a very simple lens-testing strategy:

1.) Mount lens.
2.) Capture photo.
3.) Repeat.

Any problems should show themselves shortly. There is no need to hunt them down. They will find you.

Barry,

This is a great article! I bookmarked it (I won't say for future use, because I promised my wife that I completed the range 8-200, so I will not be buying another lens soon... I said NOTHING about a teleconverter though..).

Thank you!

I have a new lens myself so I know where you are coming from. I haven't tested mine yet except for an introductory shot of the bookshelves. This proves definitively that books made from trees remain indispensable.