What is Focus Breathing?

Some lenses change apparent focal length during focus due to their optical design

“Focus Breathing” is a term photographers use to describe changes to apparent focal length as focus distance changes. The end result is a different angle of view depending on where the lens is focused.

Where Focus Breathing Becomes Problematic

• Focus-stacking: When you plan on combining multiple photos captured at different focus distances. The change in focal length leads to slightly different angles of view between shots, which can result in problems when merging and aligning images for stacking. This is most pronounced in macro photography, where even small changes in magnification can lead to profound challenges for stacking.

• Videography: Focus-breathing is a bigger problem with videography, as changing focus can result in changing the framing of the shot. For most still photography, however, it’s a non-issue.

Workarounds for Focus Breathing (especially for macro photography)

• Lens selection: Choosing lenses known for minimal focus breathing is practical advice for focus-stackers who want a simple solution with minimum additional accessories.

• Advanced stacking software: Tools with intelligent alignment and focus-breathing correction become more valuable when using lenses with noticeable breathing. My choice: Helicon Focus

• Hybrid approach: Some macro photographers use cinema lenses (designed without focus breathing)or older manual-focus designs, accepting other trade-offs for cleaner stacks.

• Use a focusing rail: A focusing rail allows you to manually set the lens at a single focus distance/magnification and then move closer to your subject by turning a fine screw. The camera mounts to the rail via a clamp.