So you're buying a second hand lens - what to look for?

When you are buying a second hand lens, it's always a nervous business. Since there is no warranty available it's important to test the lens before you hand over the money. Anyone that won't let you do this is a loser with something to hide. Walk away. Note this is not how to review a lens - this is only scoped to a quick test before you walk away with your new glass. There are common problems to all lenses to look for: look for dings and scratches in the casing that might indicate it has been dropped smooth movement of focus ring both manually and automatically aperture can be set (either manually or auto depending on lens) at all zooms look through the lens off camera at its widest aperture and check for no fogging inside no fungus no scratches on the camera end (other end doesn't matter much) It can be helpful to know which parts should and should not move. If the lens is supposed to be water resistant check that it's gaskets and seals are intact. Give it a shake too - nothing should rattle - unless it is stabilised - that mechanism might make a small rattle noise depending on lens brand (e.g. I know Canon IS lenses do). I suppose it would be better to listen for loose things that rattle and roll around when you turn the lens end for end and around. The source of a bad rattle would move the IS rattle would always be in the same place. Get familiar with the characteristics using a reliable impartial site like dpreview.com Test the lens on your body at all focal lengths and apertures. You don't have time to check on computer so use zoom on your camera display. I look mostly for focus and bright spot problems that could be light leakage. Particularly try and shoot into a bright area as this will help show up any dark fringing around the edges of the image.