Here’s a term that most of you have probably experienced before, but some of you may never have heard before. It’s called “focus breathing” (or simply “breathing“), and it refers to the shift in angle of view that often occurs when you focus a lens. If you’ve ever carefully composed a shot, refocused, and then discovered that your composition changed, you’ve been a victim of focus breathing.
In the video above, photographer Matt Granger offers an explanation of the term and a demonstration of its effects using the “holy trinity” of Nikon zoom lenses. “Even the crème de la crème do have focus breathing issues,” he says.
(H/T Imaging Resource)