An often overlooked part of learning about filmmaking are those tubes of glass, metal, and gizmos that act as the final step before light is turned into footage and photos. Unfortunately, the lens rarely gets love from anyone who isn’t a DP, photographer, or camera crew member. But that doesn't need to be the case! The lens is just as important as the camera, and in many cases, more so!
Lenses come in many shapes and sizes. But don’t let the structure of a lens fool you, size doesn't matter in the lens world! There are two numbers that do matter, however. Focal length and aperture. And that's what we will focus on today.
Focal length is the numbers followed by mm on the lens. For example, a Canon EF 50mm f/1.8 has a 50mm focal length, and a Tamron 17-50mm f/2.8 is a zoom lens that goes from 17mm to 50mm. The focal length indicates how much of the world the lens can see, where lower numbers are a wider field of view and higher numbers are much narrower.
Anything from 6mm to 35mm is considered a wide angle lens. This is based on the original size of the actual film strips (35mm film) that cameras used to shoot on. Nowadays, most cameras are digital but the functionality stays the same.
Wide angle lenses are used to, more often than not, show large spaces or groups of people. Because of how much of the world they can show, the lenses have interesting effects on how the world looks. If you have ever seen a 90’s skateboard montage, you're probably intimately familiar with the fisheye lens, which shows so much of the world that it actually warps the image. Now that's the most extreme example of a wide-angle lens, but the fact remains that if you want to capture a large area, wide angle lenses work best.
Anything from 36mm to 80mm are considered the normal or “comfortable” focal length. Historically, the 50mm lens has been the standard for normal focal length because it's closest to how our eyes see the world if you close one eye. These standard lenses are usually the workhorse lenses because they don’t surprise the viewer with any field of view effects or warping. These lenses are great for showing small groups or single subjects on screen, as they are not incredibly intimate like telephotos but not as drawn back as wide-angles. They can end up with some slight of effects of both.
Finally, the telephoto lens, which uses anything from 85mm to 57,600mm (Hubble Telescope). These lenses are the most striking compared to the human eye. The effect of zooming also has interesting effects on how backgrounds appear on the screen. Whereas wide-angle lenses show the background as very far away, telephoto lenses compress the background and make it seem very close. Telephoto lenses are frequently used to show intimacy, as they force subjects closer on screen but they also are used to make the scene feel claustrophobic and tense as the world bears down upon the subjects.
The aperture number shows how much light the lens can let in. The lowest range of the aperture is denoted by the f/ or 1. on the lens front. The lower the number, the better the lens is at shooting in low light conditions and getting a shallow depth of field. This is because, as the aperture widens (the f/stop number gets lower), more light is let in. Many filmmakers like lenses with a low f-stop because you don't need as much light to get the image you want, giving you much more precise control over your light.
In the end, as much as cameras and lenses matter, nothing matters more than the story. So before you go out and purchase gear, focus on your story and make sure you are passionate about what you want to tell!
Once you're comfortable with your project, an understanding of how lenses work and when to use them can only help your project look better!