How to buy a used traditional mechanical SLR camera

Lens Full open aperture to the bright light to see, no scratches, mold, and serious dust, off the film; and then check the aperture level level is smooth, block change is clear, no rust on the aperture no oil; zoom adjusting ring is also smooth rows, damping moderate, this lens is basically no problem.

Camera body Check whether the shutter works properly in all gears, whether the gear speed is clear, self-timer B door are good, it's OK; metering is best if you have a camera with correct metering or a light meter Check against.

Finally, install the lens to see how it works. (It's best to negotiate a test shot)