|Can you spot the problem with this one?|
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:
- 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.