Choosing Exposure for Coin Photos

Coin Photography – Choosing the Best Exposure

There are eleven pages about photographing coins:

Black Background — White Background — Photographing the Edges — Using Extension Tubes — Choosing the Best ISO Setting — Choosing the Best Aperture — Choosing the Best Exposure (this page) — Editing the Background — Keeping Detail in the Highlights — Processing Your Image — Some Final Tweaks

When taking a coin photo, it's essential to get a decent depth of field, which means setting the aperture correctly. As shown on the previous page, I find somewhere in the range f8 to f16 to be best. The next question is how to find the best exposure time.

It's quite possible to let the camera calculate this by setting aperture priority. But care is needed. Left unadjusted, a camera will try to balance out the picture so that if colour tones were removed, it would average a neutral grey. Even if you have a spot focus option that sets exposure based on only a small part of the frame, the camera will attempt to mute your silvers and brighten your bronzes. Also, shiny highlights and dark areas can both fool the camera.

Here is a set of 5 shots of a denarius of Faustina Junior. These are Photoshop thumbnails, and the exposure compensation ranges from one stop under to one stop over at half stop intervals. The best of these is half a stop overexposed.

The next image is a similar range of thumbnails of a small bronze coin from Pergamon. This time, you can see that the best shot is half a stop underexposed.

As a rule of thumb, this works for me. Bronzes, half a stop under; silvers, half a stop over; neutral tones (such as heavily toned silver coins), no adjustment. It's worth trying a full stop over for exceptionally shiny silvers to see if you get a better result.

There are eleven pages about photographing coins:

The content of this page was last updated on 27 January 2011