Canon EOS 6D: From Snapshots to Great Shots

Selecting the Proper ISO

A lower ISO setting generally translates into cleaner images and more accurate color replication. But there will be times when you need to increase your ISO in order to get a properly exposed image, especially in low-light situations such as shooting landscapes at night. This choice, however, comes at a cost. The higher the ISO, the more noise is present in an image. Noise looks like grainy artifacts (that can be multicolored) and tends to degrade image quality. Take a look at Figure 6.6, which was taken with an ISO of 2000. In order to use a shutter speed of 30 seconds (the maximum the 6D can shoot at without a remote shutter release cable), I had to use an aperture of f/3.5 and ISO 2000 to properly expose Mount Fitz ...