Oct 1, 2021
What’s the best focal length for film?
Wouldn’t it be great if it was that easy? Just set one number, remember one detail, or buy one lens, and then you’ll never have to think about focal length again.
Unfortunately, choosing the best focal length for your video is a much more layered decision — not unlike choosing the best camera.
Filmmaking is an artistic practice, so there’s no “perfect” answer to this question. Every creator approaches each project with a different vision or idea; that means the technical details (camera settings, gear selection, etc.) are going to change based on the situation.
Context plays a big role here. So does the location and the nature of the project. So rather than trying to figure out what’s the best focal length for video, let’s look more at some of the most reliable choices for a couple of the most common projects you might work on.
Before we get too deep in the weeds, let’s at least give a brief overview of what focal length is and how it actually affects video footage.
Focal length, at the absolute simplest level, is a measurement of how much of the scene will be captured on film. It’s usually measured in millimeters (mm), and it does not measure the length of a lens (even though that’s how it’s often presented).
From a more technical perspective, “focal length” measures the distance between where the light meets the lens and where the image forms on the camera’s sensor. That determines how much information is able to be captured throughout the filming process.
In other words: The longer the focal length, the narrower the angle of view and the more clarity you get. The shorter the focal length, the wider the angle but at the cost of focus.
Focal length is a balancing act between the angle of view (amount of stuff) and magnification (depth of field).
Focal length is a completely subjective thing. It’s like choosing which shirt color to wear, or what kind of flavor syrup you want in your latte.
Except in this case, your focal length does have some effect on your footage’s depth of field. That can be an artistic decision to guide the viewer’s eye, or it could be a way to get the most out of a less-than-ideal location.
A better way to approach this question is thinking about which focal length ranges are common in certain shots/situations, and what exactly those choices accomplish.
Maybe the best way to illustrate this is by looking at “talking head” videos, namely in the form of interviews and vlogs.
The most convenient thing about an interview is that your subject and background will (almost) always be stationary. You won’t have to worry about interruptions, and you can frame your shot to avoid distracting viewers.
But that also means you’ve got a decision to make: Do you go for a wider focal length to keep the focus on the subject, or do you choose a focal length that highlights where you’re filming?
35mm is the go-to focal length for most interviews, standardized by both “commercial” promos and documentaries. This particular width brings in a lot of background pieces, which helps set the tone for corporate videos, testimonials, etc.
But a 50mm lens is much closer to what the human eye sees on its own. Going this route will feel “natural” almost instinctively for audiences, even if it limits your creative control and ability to pull in depth from behind the subject.
Another important thing to keep in mind is your subject’s comfort level. Someone who is self-conscious about a specific feature or characteristic might actually want you to focus the audience’s attention on different things. Or maybe you’ve got a very bombastic personality and you realize you want to capture (or hide) their wild hand gestures.
A comfortable subject is the best way to shoot a natural-feeling interview, so you’ll want to take that into account if at all possible (even if it means a little more work on your part).
YouTube creators all tend to frame their vlogs similarly, and that’s created a trend that evolved into an unofficial standard. The 18-35mm focal length may seem like a wide range, but anything included here would capture your face and also show off your studio/room/location.
A big part of why people connect with content creators is over shared interests. Chances are you’ve watched vlogs and picked out cool elements in the background, whether that’s a planter or a Funko POP! or a poster. So you want to include that in your depth of field, but not at the expense of your face.
Here’s an example that shows the effects of different focal lengths in this type of situation:
Perhaps the most valuable point in that video is that idea that camera settings can actually affect your viewer’s emotional reaction. So choosing the right focal length isn’t just an artistic choice or a technical move — it’s helping craft the way an audience will experience it.
The mark of a great filmmaker is finding ways to use every tool and technique to improve their work’s visual storytelling. It's not unlike Western films using the cowboy shot, or epic-scale tracking shots in war films.
And just like framing and camera angles can help you build an emotion or set a tone, focal length provides a pretty clear avenue for directing a viewer’s eye in your footage.
So now we get to the complicated part: Figuring out what reaction focal lengths create when paired with angles, lighting, etc. Just knowing it’s a storytelling tool doesn’t exactly tell you how you can use certain lenses/focal lengths to your advantage.
The only way to figure out what the best focal length for video is comes down to the combination of all of those parts. And while that formula will change project to project (or even shot to shot), let’s look at a few specific examples of how focal length was used to enhance and even carry the storytelling in a scene.
Let’s start with everyone’s favorite example of focal length as a storytelling tool: Orson Welles.
In addition to being a masterful filmmaker, Welles also loved to use lenses with short focal lengths. He could pack a lot of depth into each shot, and his reliance on that style also helped distort the visuals to further establish his efforts to create strange and off-putting films.
Here’s a look at Citizen Kane, Welles’ masterpiece and an example of the 25mm focal length:
There’s a reason why this scene is often cited and analyzed by filmmakers: long take, tracking shot, depth of field, etc. Every piece of the framing creates a shot that could stand on its own without the rest of the movie, and it would still influence filmmakers today.
Rather than build up how Copolla’s lens choice ratcheted up the storytelling of The Godfather, let’s get right to an example:
To be clear, this isn’t a specific focal length breakdown. But this video does analyze Copolla’s storytelling and how much of it relies on framing.
Each shot in this video takes advantage of the 40mm focal length by keeping us close to the characters, allowing us to pick out the finer details of their expression and immediate surroundings. That tells as much of the broader story as the dialogue or action do.
To be clear, choosing a specific focal length for a project isn’t uncommon. Think of your favorite directors and there’s a good chance they’ve got a specific lens or framing style that they default to either instinctively or as a creative choice.
It’s no different than a painter who constantly depicts the ocean, or a musician who’s always implementing a particular instrument in their work.
Many artists have a hallmark or signature quality to their work, and because focal length adds so much to how a film’s story is presented to an audience, it’s no surprise that directors approach their work with that in mind.
Again, this ties back to the idea of the best focal length for video and the fact that, at the end of the day, that just doesn’t exist. The “best” option will depend entirely on your personal preference, the needs of the project, and — if we’re being honest — the gear that’s available to you. And there’s nothing wrong with that.
Ridley Scott shot Alien on a 75mm anamorphic lens. Alfred Hitchock defaulted to a 50mm on many of his projects. Steven Soderbergh obsessed over an 18mm lens for Moonlight. Steven Spielberg has basically married his directorial career to the 21mm focal length.
The good news is that the door is open. Sure, understanding focal length’s role in framing will get you started. And researching what your favorite directors use will help you visualize that knowledge. But the only thing that should affect your choice of focal length is your own creative vision, whether you’re working on a feature film or a client project.
Like everything else in the creative or filmmaking process — like which shot types you experiment with or which audio equipment you buy — the choice is up to you.
To wrap things up, let's attempt to take everything we learned above about focal length and explore how you can actually use these different focal lengths for your own projects.
From short focal lengths to wide angle lenses and telephoto lenses, the angle of view for a project will always be important to explore. For some people a focal length will just be a number on the side of your zoom lens.
And we all know that the equation to figuring out the equivalent focal length for any project can be tricky to calculate once you start taking other factors like a crop sensor or basic crop factor. Yet from zoom lenses to telephoto lenses with a fixed focal length, your angle of view can still vary greatly.
However, if you're working with a solid DP who understands focal lengths and can work with prime lenses and your camera sensor, these focal lengths become much more important.
If you'd like to keep reading up on focal length and how to work with different focal lengths (whether that be from a wide angle lens, a zoom lens, a telephoto lens or even a crop sensor camera), check out these additional articles from the Soundstripe blog below.