Focus breathing is a quirk that a lot of lenses have that can make your image look really wonky. In this video, we're going to look at what focus breathing is, how it happens, and how to fix it. And stick around to the end where I'm going to give you some tips on how to choose lenses, if focus breathing is a concern for you. So first we need to really look at what focus breathing is. And in simple terms, it's just when the focal length changes when racking the focus. Or in other words, it's when the camera slightly zooms in or out, when the focus point is adjusted. This is especially apparent in video because you can see the actual change in focal length or the breathing as it happens in real time. And this is even more apparent with lenses that have a high degree of focus breathing that are also autofocus lenses, because as that autofocus hunts around for its subject, that change in focal length or the change in the field of view can really make things look kind of weird. Now, slow smooth changes in the focus are generally less of an issue, but are still not very desirable, especially in higher end productions. Focus breathing happens from a technical perspective because the glass elements on the inside of the lens are physically moving to change the focus point. And this is exactly the same way that the glass elements inside the lens move to change the focal length. So as you zoom a lens in and out, those glass elements move back and forth. The focus does the same thing, and sometimes moving those focal elements will have a zooming effect as well. And manufacturers do their best to minimize or eliminate focus breathing by optimizing the size, position, and shape of the elements within the lens, but especially in budget lenses, it becomes difficult to eliminate that completely. So now we're going to look at a few different ways to fix focus breathing. And the first option really is the best one, which is to prevent it in the first place. And because we live in the beautiful times of YouTube reviews, it's usually pretty easy to find comprehensive reviews on a particular lens. And oftentimes the reviewer will include information on how much the lens might breathe. And so we can obtain that information pretty easily. And if you're really dead set on having no focus breathing whatsoever, most high-end photography lenses and the vast majority of good quality cinema lenses will have minimal to no focus breathing, really it starts to become a problem with the more budget lenses. The second option is that a lot of modern cameras are actually starting to come with a lens breathing compensation feature built right into the camera body. And this is where the recorded image is slightly modified, slightly cropped in to fix the lens breathing that might be apparent. The downside is that there's a limited number of cameras that come with this feature. And it's almost exclusively a brand specific feature. So if you're using a Sony camera, it's only going to work with select Sony lenses. If you're using a Canon camera, it's only going to work with select Canon lenses. So there's some limitation there, but it is a nice feature to have available. The last resort, if you've got focus breathing in your recorded image and you need to fix it, is to look for a software solution. Now Sony has a software called Catalyst Browse, which allows you to load in footage from certain Sony cameras and look at the metadata that's recorded to the video file and actually fix some of that focus breathing. But again, just like the lens compensation feature, it's limited to certain cameras and certain lenses. One final solution that you can look at is right in your video editing software. You can do something like using keyframes on cropping or zooming in and adjust those keyframes so that as the focus breathing is happening, you're maintaining a constant field of view or a constant zoom factor. So now let's go through some quick tips on how to choose a lens based off of several different factors when it relates to focus breathing. The first tip is who's your client? Who are you actually making the video for? Are you making it for yourself? Are you making it for a small business? Is it for social media or is it for an indie film or a high-end client? Because depending on who the end client is, they may or may not care or even know what focus breathing is. Tip number two is what's your budget? If you've got a very healthy budget, then you can purchase higher end lenses, which is never a bad investment. Lenses will typically outlast any of the camera bodies that you have. They maintain a good resale value and they'll give you great quality images for years and years to come. And so if you can afford to purchase those higher end lenses, then focus breathing can just be prevented altogether. Now if you're like most of us, there's probably going to be a time that you're going to be purchasing budget lenses. And that's where going online and looking at some of the reviews that are available to decide, hey, how much focus breathing does this lens have versus this lens? What features does this lens have versus that lens? And which ones are going to be most important to me? The third tip is really to think about what type of things that you're actually shooting. If you're doing a lot of handheld footage, if you're doing things on the gimbal, if you're moving around a lot, focus breathing is a lot less noticeable than it is if you have a locked off shot on a tripod and you're going to be doing a lot of rack focusing from subject to subject, where focus breathing is going to be a lot more apparent. And so if you know that you're shooting a lot of moving scenes, then focus breathing maybe isn't as much of a concern. Accurate auto focus might be a bigger concern or in body stabilization or in lens stabilization, maybe a bigger factor for you than focus breathing might. Whereas if you're doing a lot of things where the camera will be locked off on a tripod or maybe is doing slow movements on a slider and you will be changing focus from subject to subject, then the change in field of view, the change in the zoom is going to be much more noticeable and that may be a bigger factor when selecting a lens. And the last tip that I'll leave you with is you really need to decide to you care. A lot of times a lot of the factors and attributes of a lens are picked apart by filmmakers and videographers and people who are very technical and understand all these different attributes. And of course, if you're working on a high end production, it's going to be important to pay attention to all of those factors. But again, most of the time you're audience, people who are viewing things on social media, even if you're making an indie film, most of the time the viewer is not going to notice a lot of those small quirks about a lens, it's really going to be you and other filmmakers that are going to notice it. So you need to decide, hey, what's the most important thing to me when it comes to making my video? Is it going to be accurate auto focus? Is it going to be lens stabilization? Is it going to be the image quality or the maximum aperture? Is it going to be the character of the lens? And again, really need to decide what are the most important factors to you and is focus breathing one of those or is it at the top of the list for you? So I hope this video was helpful for you to understand what focus breathing is. I'll have a video coming out soon about another attribute of lenses called par focal, which is almost the inverse of focus breathing. So that'll be coming out soon, so keep an eye out for that. And if you did get some value out of the video, I appreciate it. If you hit that like button, hit the subscribe button, and I'll see you in the next video.