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08-10-2010, 12:43 PM   #1
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lens evaluation

Just got a new 70-200 and 17-50 from Tamron. Can someone simply give a step by step way to evaluate the lenses. What to photograph, what to look for etc.

maybe we can sort of standardize the approach so when talking about a lens everyone is on the same page.

08-10-2010, 12:52 PM   #2
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Take pictures of different things and look at them. Worry about charts later.
08-10-2010, 12:57 PM   #3
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step one: mount first lens on the camera
step two: go out and take a lot of pictures, across the aperture range and across the zoom range.
step three: download them on your computer
step four: do you like them? (colors, contrast etc) are they focused where you were focusing? (if not is the lens or your technique or the camera?)
repeat steps 1-4 with the other lens. Sometimes it takes 2-3 outings to decide...
some people will advise you to use test charts, my take on it is to use the lenses in real life situations and it'll really give you the idea of lens' performance....
08-10-2010, 07:36 PM - 1 Like   #4
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Go out and take pictures.
Unless you are fairly well versed in testing camera gear, running ad hoc tests from web site advice will probably result in less than accurate (and probably less than satisfactory) results.

I swear, most of the people who complain about how their equipment failed this test or that one have probably screwed up the test, and therefore the results.

08-10-2010, 07:58 PM   #5
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If I just dropped over a grand on new lenses I would want advice on how to know if they are of quality, especially since there are documented cases of good and bad copies of each of these lenses

c'mon people help a guy out instead of being so cavalier

if I had an effective system of testing copies I'd tell you but I don't have one
08-10-2010, 08:19 PM   #6
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QuoteOriginally posted by future_retro Quote
If I just dropped over a grand on new lenses I would want advice on how to know if they are of quality, especially since there are documented cases of good and bad copies of each of these lenses

c'mon people help a guy out instead of being so cavalier

if I had an effective system of testing copies I'd tell you but I don't have one
I can't give any quick answers, but I can give some starting points:

Focus Testing - photo.net

Lens testing - or why you can't trust lens tests

Focus Fallibility: Lens Test Fallacies - SLRgear.com!

lens testing
08-11-2010, 06:22 AM   #7
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QuoteOriginally posted by future_retro Quote
If I just dropped over a grand on new lenses I would want advice on how to know if they are of quality, especially since there are documented cases of good and bad copies of each of these lenses

c'mon people help a guy out instead of being so cavalier

if I had an effective system of testing copies I'd tell you but I don't have one
I think the best way to test out a lens is to take some pictures. That will tell you about its performance with your shooting style and technique. So is it a good lens AND is it a good lens for me. But yeah, I can see that one would want to pick up a turkey early on, when returns/exchanges might be possible, and that test charts might detect subtle issues sooner.
08-11-2010, 10:06 AM   #8
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QuoteOriginally posted by Wheatfield Quote
Go out and take pictures.
Unless you are fairly well versed in testing camera gear, running ad hoc tests from web site advice will probably result in less than accurate (and probably less than satisfactory) results.

I swear, most of the people who complain about how their equipment failed this test or that one have probably screwed up the test, and therefore the results.
I bet I am guilty of this, especially testing manual lenses wide open on my DSLR, where its difficult to achieve exact focus, with very shallow DOF and no split-screen.

My 2 cents would be to try to pick up a copy of "The Lens Book" by Hicks and Schultz where there is a little section on lens testing. Another thing to do is shoot two lenses side by side, with everything else the same. But if you've just bought a lens new, would you really want to have to sell it, if it did not perform as well? The only reason I've done lens testing is because I am buying second hand kit, and want to know its not bust before I use it for something critical, like taking pictures of a new born baby..."if it ain't broke, don't fix it".

Somewhere in the Hicks and Shultz book it talks about photographers obsessing over kit they never use, buying fast apertures they never use and that if you are printing out at 8x10" or smaller, any zoom is likely to suffice.


Last edited by whojammyflip; 08-11-2010 at 10:14 AM.
08-11-2010, 11:07 AM   #9
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My only test is to set up my lens on a tripod, and shoot my booksheld at various apertures. This gives me an idea of what to expect regarding sharpness and exposure. Then I can go out and shoot with the lens, knowing its limitations. I sometimes try to MF on the bookshelf just to see if AF is reliable. It always is.

If, after using the lens, I suspect AF might be off, then I take out my tripod and shoot adistant subject while varying the AF offset in my K20D. I then look at the images and decide what's the best setting. I did that with my FA 100-300 f4,7 because it was sharp at close distances, but less so at infinity.

Apart from that, as others said, using the lens is the best test. That's what convinced me that my DA21 is special.
08-11-2010, 03:08 PM   #10
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QuoteOriginally posted by future_retro Quote
If I just dropped over a grand on new lenses I would want advice on how to know if they are of quality, especially since there are documented cases of good and bad copies of each of these lenses

c'mon people help a guy out instead of being so cavalier

if I had an effective system of testing copies I'd tell you but I don't have one
That's the problem though - running an effective test takes expertise that few people asking about this here would have, and a few words of advice in a forum isn't going to give them that expertise. Wheatfield is absolutely right - "most" people who run tests on their new gear probably screw up the testing in such a way that they either find "problems" that aren't there or else miss the actual problems that are there. The way to help people out is to advise them on the best way to avoid that mistake - and the best way to avoid that mistake may well be to not try to do such tests in the first place but to simply rely on real world experience.
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