Our industry uses a lot of specific jargon, and every once in a while some of those terms make their way into more everyday usage. But, that doesn’t mean people are using those terms correctly. So, we figured that from time to time we’d try to help clarify some of these terms in case you ever find yourself a part of a production and don’t want to feel out of the loop.
Today’s topic is focal lengths.
Even if you’re unfamiliar with the specifics of different focal lengths of lenses and how they affect images, you’ve probably at least heard terms like “zoom in,” “zoom out,” “wide,” “tight,” used in all sorts of scenarios.
To truly understand all of this would require a level of physics that I’m certainly not equipped to go into. But all of that is not necessary to learn the basics and be able to speak more intelligently about the subject. So, let’s dive in!
The proper definition of “focal length” is the measure of distance between the nodal point of the lens and the camera’s sensor. For what it’s worth, the “nodal point” is simply the point where light converges in a lens. So, the first thing to remember is that the focal length is a part of the lens you are using, not the camera itself.
The reason focal length is so important in photography and video production, is that the difference in focal lengths can make a huge difference in what the camera “sees.” Do we want to focus on something specific? Or do we want to see a wide expanse? Do we want the frame to be as clear up close to the camera as it is in the background? Or do we want to really separate our subject from the surroundings? All of this can be greatly changed by the use of lenses with different focal lengths.
There are a variety of lenses made at different focal lengths, but mostly they fall into three main categories. Let’s have a quick look at each category and what makes them unique.
Standard/Normal Lenses
Standard lenses have a focal length between 35mm and 70mm and see images in a way that is very similar to how our eyes see the world. For this reason, standard lenses are kind of a default lens for many photographers.
Wide-Angle Lenses
Any lens with a focal length smaller than 35mm is considered a wide-angle lens. These allow the camera to view a very wide view of the world and are often used to depict landscapes, and other large scenes.
It should be noted, however, that as you get a shorter and shorter focal length, you will see more and more distortion in the image itself. In fact, lenses with a focal length of 8mm-10mm are often called fisheye lenses and the effect on the image, especially around the edges of the frame, can be interesting and even a little unsettling. For great examples of this type of lens in Hollywood films, check out anything by Yorgos Lanthimos or one of my favorite examples, No Sudden Move, directed by Steven Soderbergh.
Telephoto Lenses
Any lens with a focal length longer than 70mm is considered a telephoto lens. These lenses allow the camera to feel much closer to their subjects and are used commonly in wildlife and sports photography. These lenses also have the added feature of compressing the foreground and background, making things feel much closer together than they really are.
And, as you might imagine, as the focal lengths of these lenses get longer, all of these effects are intensified. Most telephoto lenses are in the 70mm-300mm range, but there are lenses with MUCH longer focal lengths available (though very specialized and expensive). My favorite example of this kind of lens in a Hollywood film is this scene from Tinker Tailor Soldier Spy where they use a 2000mm lens to add a great deal of tension to a scene by making it look like a landing plane is incredibly close to two people having a conversation.
As with almost everything in photography and filmmaking, it is important to learn how the hardware you are using can affect the imagery you are capturing, but the real magic comes with how an artist can play with these tools to convey exactly what they are trying to convey in the most efficient and creative ways possible.
