Aspect Ratio Is More Than Just A Number

How 3:2, 4:3, and 16:9 affect the way we see the world.
 

- Seth Shostak

BEFORE YOU BOUGHT YOUR LAST CAMERA, did you weigh the pros and cons of the sensor’s aspect ratio? My guess is no—not in the face of more solemn considerations such as style, trim, and a boastful shoulder strap.

However, aspect ratio has a baked-in influence on resolution, lens weight, and how you’ll display your artful efforts. And in most cases, the ratio has been set, not by what would be best for you, but by ad hoc decisions made before the Spanish American War.

Aspect ratio is the width-to-height ratio of your sensor. For a full-frame DSLR, the sensor is 36x24mm in size, for an aspect ratio of 3:2. Ditto, 35mm film. For non-full-frame cameras, the sensor is smaller but the aspect ratio is usually the same.