How do I test a lens

[Colnago]

... to see whether I got a good copy or not.

Hi members of clubsnap,

This is my first postings, hope you guys be gentle ok. . I'm really curious how do u guys test the lens? Maybe some of the experts out there can help me? From what I understand, mount ur camera on tripod, and set to Aperture mode & focus on a subject. Start taking photos from F2.8, F5.6, F8, F11 and so on. View on ur pc at 100%. Am I right on this? Any more info on this lens testing method is very much appreciated. Thanks.

 

[ortega]

Welcome to CS

Firstly what are you testing for?
So after testing and the results are not up to par,
what do you do with the lens?

Just read the reviews and leave the testing to the experts.

Cheers!

Just shoot it!

 

[Xpose]

cheack the af motor? Check if it can go from min to inifity smooth and back

 

[Witness]

open up the aperture to maxmum and look thru the back for FFD...

fungus
fog
dust...

cheers..

 

[user111]

check for fungus, infinity focus, AF, loose parts, strange sounds, cosmetic wear, version(mark1? mark2?), filter size, hood, case, box, age, warranty, ..

 

[Colnago]

Ok, what about the sweet spot? I know some lens got sweet spot right? I hv the 70-200F4 L, SP 90 DI and 28-135 IS USM. Any idea what are the sweet spot for these lens? Thanks for all the replies.

 

[espn]

The sweet spots for all glasses are mostly the center of the elements, thus at about f/8, most glasses performs it's best, thus the term 'sweet spot'.