Canon EOS 6D: From Snapshots to Great Shots

Focusing in Low Light

While the 6D has a great autofocusing system, it can (like many DSLRs) struggle to focus in low-light situations. In order to overcome these challenges, there are a few things you can do.

First, you should know exactly how focus is achieved. Have you ever pointed a camera at a clear blue sky and tried to use autofocus? Most likely your camera struggled as it hunted around the frame to find focus. Why? The answer is contrast. All focusing systems need to find points of contrast; that is, where dark elements touch lighter elements (Figure 7.8). If your camera struggles to find focus when the sky is perfectly clear, it should have no problem achieving focus when clouds are present. The blue of the sky is darker than the white ...