Camera lenses have many optical limitations and issues you’ll have to wrestle with as a photographer and videographer. One of the most common issues you’ll see across the board is called focus breathing. This can have negative side effects on both photos and video, which can occur on nearly any lens, but some lenses experience it worse than others.
If you don’t know what focus breathing is, it’s worth finding out to see if it affects the kind of content you create. In this article, we’ll cover exactly what it is, what causes it, and how you can avoid and eliminate it in your shoots.
What does Focus Breathing mean?
Focus breathing is a term that describes what happens when you adjust the focus point on your lens. This is most noticeable when changing from the minimum focus point of the lens to infinity. It causes the magnification and field of view to change slightly on the lens.
The quality of the lens often dictates how much change you’ll see between images. Some lenses are even specially manufactured to have it minimally for cases where this is important.
What Causes Focus Breathing?
Most lenses on the market today feature internal elements that adjust the focus point of a lens. This lens build is the most popular because it means the lens doesn’t move at all when focusing, nor does it get larger or smaller, but it does come with one downside. The internal moving elements when you focus your lens can cause focus breathing.
When your lens focuses, some elements move while others stay still, causing a slight change in focal length and field of view. This effect can be amplified or silenced depending on the lens. Usually, the higher the lens quality, the less you’ll experience.
The change in focal length is only present at the closest possible focusing point. The change in focal length can vary depending on the quality of the lens. Focus breathing in lenses only causes a decrease in focal length, rather than an increase.
If you want to test your lenses, simply adjust the focus to the minimum and take a photo. Then, adjust the focus to infinity and take another photo. Compare the two photos to see how much the focal length has changed.
How to Avoid Focus Breathing
To avoid focus breathing in your shoots, avoid scenes where the focus point in your images or videos changes from very close to very far. For photography, this won’t cause problems unless you’re focus stacking or need to be able to do image comparisons at varying focal lengths.
For videography, focus breathing can hurt the production quality of your video. To best avoid it in your videos, you should avoid using rack focus: a videography technique where one part of the image starts in focus and ends out of focus, or vice versa. This technique can look fantastic when done correctly on a high-quality lens, but lenses that experience this significantly, don’t work well for this kind of shot.
If you still need to shoot a scene with multiple focus points but want to minimize this, move your two focus points closer together, or step back further away from the scene and zoom in. The further away you are, the less the focus point needs to change from one subject to another. This will result in minimal focus breathing. While it’s impossible to avoid it completely, this can easily be minimized when using the right techniques.
How to Eliminate Focus Breathing
If focus breathing is causing a significant disturbance in your shoot, there are a few ways to eliminate it. The easiest way, unfortunately, is also the most expensive. It involves simply purchasing a new lens. Many lenses advertise minimal or no focus breathing. These are specially crafted to offer the least amount possible. If you’re experiencing extreme issues, it is likely due to your lens. Purchasing a new lens can help to eliminate it altogether. For videographers, this is the most reliable way to eliminate it from your footage moving forward.
For photographers, you can eliminate focus breathing in post-processing (to an extent) in Photoshop:
- If you need two images to look exactly the same, use Photoshop’s layer align feature to eliminate it in your images.
- Simply load both images into Photoshop and select both layers. Then, go to Edit > Auto-Align Layers and select Auto.
- You should then see both layers become perfectly aligned.
This works particularly well for focus stacks, where you must selectively combine images to retain sharp focus from front to back. In most other aspects of photography, this isn’t a big issue and you don’t need to worry about focus breathing.
Conclusion
Focus breathing is certainly not a problem that will be going away anytime soon, but you can expect more brands to place emphasis on releasing lenses with minimal focus breathing. It can be a real headache for photographers and videographers alike. If this causes problems for you, make sure you look out for lenses that advertise having minimal focusing breathing for the best results.
