How to check for sharpness when getting lens?

[alant]

Hi, I was reading through some threads here on what to check for when getting 2nd hand lenses. And read that some people say that the same model of lens from the same brand can have different degree of sharpness depending on the copy you landed with. May I know how does one go about checking for sharpness to ensure that one has the best copy? I'm sorry if there's a similar question being asked before, maybe you could help post the thread reference here so that I can go read it up. Thanks.

[ShawnQuah]

Originally Posted by alant Hi, I was reading through some threads here on what to check for when getting 2nd hand lenses. And read that some people say that the same model of lens from the same brand can have different degree of sharpness depending on the copy you landed with. May I know how does one go about checking for sharpness to ensure that one has the best copy? I'm sorry if there's a similar question being asked before, maybe you could help post the thread reference here so that I can go read it up. Thanks.

When you buy a second hand lens, it is a MUST that you bring a body to try on the spot. It will be good if its a DSLR as you can see the output of the lens immediately

The term "sharp" is actually very subjective. I don't know if you have came across people commenting that lens too sharp (causing pictures to be very fake), and also some people find certain lens that is too soft but in actual fact is very natural

[alant]

Wow sounds tough...But I also read that some say bring camera not good enough as can't see overall, so bring notebook to test? Is that too extreme? Then again there's possibility of the lens being sharp but my hand just at that moment not steady enough so how? Thanks for the inputs Shawn.

[AlteredVision]

Bring tripod also Not to mention cable release / timer. (Joking, but you can take seriously if you want)

Or if you're buying from a shop like Cathay Photo, you can just borrow one of their display tripods to use.

[alant]

I'm not into such extremes. The thing that confused me is that is it true different copies of the same lens from the same brand, does the sharpness really differ? And how to check?

[qing02051981]

I think TS is talking about prime lens?

[lingus]

a few ways to ascertain lens quality is to check for edge distortion or the quality of bokeh (the off-focused blur zones) in the pictures, or on the lens iteself, determining the number of lens elements within (the more the merrier), if the elements are spherical and multicoated etc etc..

if you wanna go full technical on the checking, check out this site: http://www.bobatkins.com/photography...sharpness.html

[racoon31e]

Originally Posted by alant Hi, I was reading through some threads here on what to check for when getting 2nd hand lenses. And read that some people say that the same model of lens from the same brand can have different degree of sharpness depending on the copy you landed with. May I know how does one go about checking for sharpness to ensure that one has the best copy? I'm sorry if there's a similar question being asked before, maybe you could help post the thread reference here so that I can go read it up. Thanks.

Bookmarked this thread from 2 years ago. See the second post: http://www.clubsnap.com/forums/showthread.php?t=244817

Hope it helps