My Focal Length is Longer Than Yours
A simple guide.
There are endless articles and videos on the interwebs that talk about what focal length is, and they can be very technical, and sometimes downright tedious. This ain’t that. What I would love to do is explain in a very non-technical way why any image, but especially people, can look distorted in weird ways. And why you might choose one focal length over another.
There are three big categories of lens focal lengths. There is a range within each category.
- Telephoto – 70mm and larger numbers
- Normal – around 50mm
- Wide angle – 40mm and smaller numbers
If you’ve ever used a telescope or binoculars you know that those optics bring far away things closer to you. This is what happens with a telephoto lens. There is generally no distortion with a telephoto lens, and this is why it is typically the choice for portrait work. These lenses also make it easier to get a shallower depth-of-field where you get the subject in focus and the background is soft, but that's another technical rabbit hole for another day.
You might also use a telephoto lens if you are a spy because you don’t have to get physically close to the subject you're tailing. People who like to photograph wild animals also tend to use this focal length so they don't disturb the animal, or so they don't get eaten by it.
Wide-angle is where you get into distortions. If you have ever looked through a telescope or binoculars the wrong way, it does the opposite – it pushes things farther away from you. In addition, it also compresses space. Realtors use wide-angle because you can compress a room into a space that fits into the image frame. It can also give the impression that small rooms feel larger. Just take a look on Zillow and you will see images of rooms where you can see the whole room, but if you look at the walls and doors, they will not be straight up and down. They will tend to be at an angle or curved. Because lenses are round. Your rearview mirrors in your car – “objects in mirror are closer than they appear” – are giving you a bit of a wide-angle view so you can see more of your blind spots.
For photographing objects, these distortions are sometimes things we just get used to seeing. A lot of our phone cameras have a wide-angle default. But when you compress space on a person, that’s when you get that look of the nose being more prominent than real life, or on a full-length portrait the feet look funny and elongated. Or any body part that is close to the lens will look overly exaggerated. You can totally use this technique on purpose for effect, but for most basic portraiture, it generally does not present people in their best light.
Normal is called normal because it is kinda sorta close to how our eyes actually see. You’re not really drawing images toward you, and you’re not really pushing them away.