Tips for buying used glass

No experience of that lens my friend but if you get it from the second hand electrical store it would be a good idea to secure some form of money back guarantee if you are not happy with the purchase. Aside from that check that there's no fungus, contacts are clean and the zooming function is smooth. If you can, test the lens with your camera while in store. Presumably that should be in order.

Good luck with your purchase.
 
Houston1863 said:
No experience of that lens my friend but if you get it from the second hand electrical store it would be a good idea to secure some form of money back guarantee if you are not happy with the purchase. Aside from that check that there's no fungus, contacts are clean and the zooming function is smooth. If you can, test the lens with your camera while in store. Presumably that should be in order.

Good luck with your purchase.

Thanks, the shop do allow you to try lenses with your camera
 
Quick way to test a used lens.

1. Cosmetic. Self-explanatory. Remember to check for internal dust, but don't get too hung up about it. A bit of dust is normal and won't show on photos. But if it's excessive, that could be a sign that something inside the lens is being abraded.

2. Mechanical. Check that all moving parts move smoothly without sticking or grinding. Primarily this is the focus and zoom mechanisms, but also check that all switches work.

3. Electrical. Check that all the electronics work. Depending on the lens that could include autofocus, IS/VR, focus distance limiter, focus preset, various focus start buttons, etc. Check also that the aperture stop-down works: set camera to aperture priority, shoot the same scene at each aperture, and check using the camera's LCD that exposures are the same. (Expect a bit of light fall-off towards the corners at wide angles and wide apertures, but no wholesale exposure changes.)

4. Optical. Find a high-contrast target and set the camera to shoot with a shutter speed which is fast enough to avoid camera shake. Focus with the target in the centre of the frame, then recompose without refocussing and shoot with the target in the corner of the frame. Repeat three times with the target in the other three corners, and then examine the photos at high magnification on the camera's LCD. You're looking for the four targets to be equally sharp. How sharp depends on the lens and other factors, but they should be the same. If they're not, that points to an optical problem - probably a decentred element after a knock or drop.

Hope this helps.
 
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