Use the search function in future. many threads on this.
you can test at the shop, but i prefer 7 days walk in so i can slowly take my time to test it out, because you can truly see the problems when u upload the photos to a computer or laptop.
test the AF but setting to largest aperture, then take a picture of words with the camera lens tilted at 45 degrees to check if the focusing point is accurate.
sharpness wise, have to see sample pictures to roughly know what to expect of each individual lens i feel.
there are some very good guides giving detailed instructions.
this mainly applies to first hand lens too.
http://www.clubsnap.com/forums/showthread.php?t=311048&highlight=check+lens
If in a hurry, ask to test on a 5D2 / 50D. The hi-res new screen really helped me with my 70-200 yesterday. Shoot text on camera boxes or newspapers. First copy from CP was soft. 2nd and third were soft AND had CA problems. Went to John3:16, and their 2 copies didn't have CA problems, but one was softer than the other. I took the sharpest of the 5.
How to see the pic is soft? Got any sample pic? Sorry, What is CA stand for?
anymore methods can use to test out the lens? But thanks for all brothers nice comments. Cheers
If in a hurry, ask to test on a 5D2 / 50D. The hi-res new screen really helped me with my 70-200 yesterday. Shoot text on camera boxes or newspapers. First copy from CP was soft. 2nd and third were soft AND had CA problems. Went to John3:16, and their 2 copies didn't have CA problems, but one was softer than the other. I took the sharpest of the 5.
That's troublesome, but, acceptable for a 2.5k lens. Imagine doing that when you are trying to buy a 50mm f1.8
Why do you need to know so many methods of checking lenses? Shouldn't you shoot some photos, gauge sharpness / detail on your screen and decide whether to buy it there and then?
Hi
One other thing.
For nikon VR lens, half-press the shutter. U shud hear some mechanical sound coming from the lens. It shud be a "repetitive revolving" kinda rythm.