How to Check a Used Camera Before You Buy

A practical camera check, step by step

1. Bring a compatible lens, charged battery and memory card. With the seller’s agreement, save original test files and note the body model, stock ID and the functions you could not check.
2. Use a static subject in good light to check single autofocus, then a moving subject for continuous autofocus. Review several images at full size; motion blur or an unsuitable setting can look like a fault.
3. Check a plain, evenly lit subject at a small aperture for recurring spots, following the manufacturer’s instructions. Compare files on another screen to distinguish image defects from display defects.
4. Do not touch the sensor, mirror or shutter, use compressed air inside the body, or force any mechanism. Sony’s cleaning guidance below gives a model-dependent procedure; use the correct manual or a qualified service provider.
5. Record results for the ports, card slots, video modes and controls you need. A short viewing cannot establish battery capacity, long-recording thermal behaviour or every intermittent fault.