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Whether you're a photography or videography beginner or just need a refresher, everything you need to know about focal length is here.
What is focal length?
Focal length is a representation of how angle-of-view and magnification converge. Focal length is almost always described in millimeters (mm). Now, what's angle-of-view, you ask?
What is angle-of-view?
When you are looking at a scene you'd like to film or photograph, you have to decide how much of it you want to capture. If you only care about a lake, and not the trees or houses on either side, then you're looking for a higher focal length.
Essentially, it's whether you want a wide look at a scene or a narrow view.
What is magnification?
You probably already have a good idea of what magnification refers to, however, to put it plainly, it's how large certain elements in the scene appear.
To refer to the lake scene again, will the lake appear large or small? If large, then a higher focal length, and if small, then a lower focal length.
But why is focal length important?
In general, focal length is important when buying lenses. It's good to keep in mind the kinds of scenes you intend to shoot. The focal length needs to match your vision.
The average human eye has a focal length of 17mm. While there are other factors involved in processing the image we see, it can help calculate a scene in front of you.
If you're shooting in a dark environment, there are some other factors to remember. Here are our top tips on how to film in low light.
A high focal length, even a 600mm lens or higher, is incredibly useful for shooting wildlife. It allows you to be far away but still get a crisp, narrow view of things like birds. If you tried to shoot that same bird from the same distance with a low focal length, you wouldn't even be able to see the bird at all.
If you are interested in filming or photographing a person up close, the focal length has to be somewhat different. Generally, you will be looking for a 70-135mm lens. This focal length range allows you to capture minute expressions and intimate moments.
When dealing with landscapes, there are many different options. It all depends on what exactly you're shooting. In general, though, a lens in the range of 14-70mm is what you should be after.
The lower focal length will allow you to see far more. If you're looking down at a valley, you might want to capture the river, the forest, and the mountain. To cram all of that in the image, 18-24mm might be the sweet spot to avoid distortion and still get an expansive view.
When to keep focal length in mind
As you can see, it's clear that you need to keep focal length in mind to achieve the look you want. When packing up your camera bag to go and shoot an indoor area, like real estate, you probably don't want a high focal length.
Rather, you would want a wide-angle lens around the 14-35mm range. This type of lens would allow those viewing the image to see more in cramped spaces.
Image of a wide angle lens
It's clear that focal length is important not merely for hobbyists.
How to use focal length?
The best way to understand how to use focal length is to look at some different kinds of common lenses. By understanding what a wide-angle or a telephoto lens is, you can gain a better idea of how focal length brings everything together.
In the range of 50-60mm, it's part of nearly everyone's kit. Minimal distortion can bring a more accurate and true-to-life view.
They are particularly useful when you don't have a lot of accessories. They typically work well with minimal, or low lighting scenarios.
We already discussed how a wide-angle lens might be useful in indoor photography. What if you're in the Palace of Versailles and want that classic view down a hallway at all the gorgeous architecture? A smaller focal length will let you see more stuff.
This kind of lens is also highly useful in landscape photography. That lower focal length of 14-40mm can add a sense of grand scale, as well as capture massive scenes.
In many ways, that grandness can convey the feeling of what you experience when seeing the Grand Canyon. You want to make sure big things don't look puny and unimpressive. Wide-angle lenses can easily solve that issue (as can that low focal length).
These can range from standard telephoto to "super" telephoto. The standard telephoto lens will range from 70-200mm of focal length. These are good "workhorse" lenses, fulfilling a variety of roles from portraits to wildlife and even landscapes on occasion.
Super telephoto lenses are used for wildlife photography and sports. They are perfect for moments when you can't be up close and personal with your subject.
How is focal length used in film and social media videos?
Let's look at three examples of focal length used in videos. We'll follow that up with a glimpse at how it can be used in still images on places like Instagram.
YouTube travel channels
The video giant itself has videos showing off how different focal lengths can impact a video. If you're watching videos about the next city you're traveling to, you might start to notice how different focal lengths play a part in the video's composition.
Take this video on the Faroe Islands. This person is using only two different lenses to achieve all the different beautiful shots you can see in the video.
First, they use a small focal length 16-35mm lens. No doubt they use this lens to fit in the massive landscape scenes they capture with their drone.
Second, they use a 29-75mm. With this lens, they can do a variety of shots, from their vlogging moments outdoors to the more cramped quarters inside a car.
But maybe you're not interested in drone footage as much, or those far away nature moments. What about capturing intimate, dramatic moments from far away?
A great example of how focal length can be used to create emotions for the viewer is this example of a scene filmed with a 2000mm lens. It's easy to understand the feeling of this video. It's as though you are sneaking up on the two characters, gaining a window into their conversation.
Beyond this, the focal length turns the long runway into a continually escalating moment. The viewer is left anxious due to the compression the focal length allows between the foreground (the two characters) and the background (the plane and runway).
Almost the entirety of some films is done on a single 35mm lens. Watching these movies evokes a sense of normality. It might even make you feel as though there is nothing "special" about the lens being used and this entirely intentional. Since this lens is closest to how a human eye might view a scene, it fits well with a film intending to tell the story of simple lives.
For a movie all about characters with a great deal of personality and depth, you gain a sense of companionship beyond the script. Even if you were to turn off the sound, you would still get the feeling of the film.
Let's look at a real estate example on Instagram. As you can see, they must be using wide-angle lenses with a fairly low focal length. When you are shooting in close quarters like kitchens or hallways, it can be difficult to capture everything with a standard lens. It's just like when you are trying to fit a large mountain range into your camera's view. Except, instead of snow-capped peaks it's cabinets and lighting!
Isn't it great that you can combine a lens for outdoor landscape photography and indoor filming? If you are interested in making video ads on Instagram, check out our step-by-step guide to make Instagram video ads.
Learn how to make amazing videos
Now that you understand focal length, you're surely ready to head out into the world and get started. But wait! There's always more to learn. Be sure to check out our blog to open up a new dimension through your camera's viewfinder! Learn about aperture, white balance, rule of thirds and more!