The DSLR Field Guide

Compression vs. Image Quality

Although storage space, primarily in the form of memory cards, is becoming less expensive, there are still advantages in being able to compress the data for a photograph, provided that the image is not noticeably degraded. The key word here is “noticeably.”

The raison d’être for JPEG in the camera’s menu is that it is both a compression method and a file format, and this is usually the format to choose when it is important to squeeze the maximum number of images onto a memory card. In addition, the recording time will usually be less than it is for a Raw file, and so the images will move through the frame buffer more quickly—all good for shooting large numbers of images continuously.

Compressing a Raw image is a ...