[aap]

hi everybody, I'd buy the len these few days, "24-105 L" haha....
btw, what is the important things when checking lens or keep attention?
thanks thanks alot buddy.....

[JSmith]

睇下裡面多唔多塵，
coating有冇花，
外表有冇花，
帶埋自己部機去試，
焦點是否正確，
對清楚保用證同鏡身serial no
俾錢
走人

[老叟]

these are professional works, and should be done by experts,
otherwise, just ignore the check and enjoy happy shooting!!!

[Obi-Wan]

1. made sure it is new --
the outer part, including the front & rear lens should be free of dust
see the mount (should be perfect without scratch),
point to light source, it should have very little dust only (but there may be bubbles in glass, that's ok)

2. made sure it works --
see whether it has out-focus problem
see whether the aperture is smoothly close/open (press step down button on camera body)
take photo on a flat newspaper, the letters on each side & each corner should be nearly the same. I have a sigma lens which can take one side in focus while the other side outside on a flat newspaper.

Last words: if u found defect AFTER buying the lens for a long time, don't bother too much.

I have a 28-85 nikon AF lens with a lot of mold, still enjoy using it. My cheap cheap EF17-85 IS lens inside have over hundreds of dust particles, still enjoy using it. U cannot notice any defect in ordinary usage.