What is Focus Breathing?
Sometimes referred to as lens breathing, focus breathing is a common problem that occurs when a lens essentially steals the focal distance as it attempts to focus on a close subject. Focus breathing impacts filmmakers in a variety of negative ways and can be incredibly frustrating. As we take a look at answering the common question from new aspiring cinematographers, “What is focus breathing?” We’re also looking at how to solve it!
Understanding Focus Breathing
Focus breathing is a phenomena with the lens that occurs when the cinematographer attempts to focus between two extremes of the lens either the minimal focusing distance (MFD) or infinity.
Basically, focus breathing is what happens or appears to be happening, when the focus length of the lens is changed from one focus distance extreme such as the minimum focusing distance to another focus extreme such as infinity.
Focus breathing can occur when working the opposite way too, such as when the lens focus goes from infinity to very close or the MFD.
Focus breathing can be incredibly frustrating to the cinematographer and, although it doesn’t always happen, when it does most will attempt to otherwise overcompensate to correct it.
What happens is you’ll notice that when you’ve got your lens zoomed to the max, it will appear to be zooming in and out very slightly.
The same can happen when attempting to film at the minimum focal distance, the appearance in the viewfinder will be of the focal length very slightly changing to zoom in or out further.
Focus breathing is captured on the raw footage when behind the camera someone changes the focus distance while they are filming and the movement is captured. This can distract the viewer and is a problem that will need to be properly planned for, and solved.
Is There a Solution for Focus Breathing?
When a new cinematographer asks, “What is focus breathing?” The next question is often, is there a solution for focus breathing? The short answer is, yes there are some ways to minimize focus breathing or the perceived adjustments that are occurring with your lenses.
While focus breathing really doesn’t impact photographers, it can really drive a cinematographer crazy.
Focus breathing typically occurs for videographers shooting with a DSLR camera that is either using a prime lens, zoom lens, or just the camera itself.
While still photographers don’t have to worry about documenting focus change, cinematographers do – and this can mean that focus breathing will throw a wrench into the entire situation.
Specialty video cameras that are built specifically for cinematography will not result in focus breathing. So that’s the first, and easiest way to solve this problem is to use a camera built for filming. However, these cameras can be incredibly expensive and out of reach for the average, starting cinematographer.
An alternative solution when we look at “What is focus breathing?” And more so, what can be done to fix it, is test out different lenses to achieve the varied focal length with the appropriate quality that you desire.
Avoid maxing the lens out to the highest value or lowest level of magnification, this way you won’t have so much of a problem with focus breathing. In the end, focus breathing is something that you’ll just have to face if you’re not using an advanced filmmaking camera.
