How do YOU check lens sharpness in a store?

I would like some tips and info on how to test sharpness of a lens in a store?
As I can't very well put up a complete test rig in a store to test ......what is the next best thing?

Dooku wrote in post #16117704
I would like some tips and info on how to test sharpness of a lens in a store?
As I can't very well put up a complete test rig in a store to test ......what is the next best thing?

You don't. There are ISO chart samples available for pretty much all lenses in TDP. You go check it there, read all the reviews, and buy the lens you like.

If its the copy variation you worry about, you buy it from a place that has a good return policy like Amazon, you test it at home, and return it if you dont like it.

Another option is to bring your camera, test out the lens on your body, make note of the lens' serial number, go home, and then look (pixel peep) the test shots. If you like the results, go back and buy that specific lens. If they sold it, repeat the process. The only down side to this is that you will be buying the display model, as I doubt most stores will let you test one from stock. The other way is bring your laptop with you, and check your test results right there.

I grab a tripod out of their store, shoot a billboard or something with text on it in live view and through the viewfinder and see if there is a visible difference zoomed in on the LCD. Then take some shots of the guy behind the counter hand held and count eyelashes in the LCD.

None of the above methods is as good as focus or ISO chart tests that you can perform at home once you have the lens (both take literally 5 minutes and tell you so much about the lens).

Keep in mind, 'perfection' is not an absolute measure, but relative to each body:

http://www.lensrentals​.com …s-is-soft-and-other-myths

bring a laptop so you can check right then and there.

Find something else to worry about? Really, I doubt there is much copy to copy difference 'tween lenses.

ISO charts are nice, but such a test is only useful at home. I am really only interested in possible copy variation which can be relatively easily tested on location without bringing much more then your own camera body.

I did such a test using only the lc screen as mentioned by several members in their replies. I took some pictures in the store like bar codes on boxes, billboards and the guy behind the counter. I did this at two different stores I buy my camera stuff and fortunately they have no problem with that.
And to my surprise I noticed a visible difference between two copies of that lens using only the lcd screen. One copy was really sharp, the other not quite so.
Although this may not be as good as doing a full test with ISO charts, I now tend to believe it still is very much useful as also pointed out in other replies. Thank you all for the information!

gasrocks wrote in post #16118695
Find something else to worry about? Really, I doubt there is much copy to copy difference 'tween lenses.

Out of calibration and decentered lenses are not that uncommon. Even the major review sites talk about rejecting lenses.

I don't, really. Take my own body in, shoot a few shots in and outside of the store; check LCD to make sure things aren't noticeably off there; if that looks good, I'll take the lens home and do the real tests there.

Run your finger along the rim of the lens. If you draw blood, it is plenty sharp