What are wide angle, prime, telephoto, or zoom lenses? The names can sometimes be confusing to a beginner, because you hear them tossed around a lot in generic ways (sometimes inaccurately), and there’s some overlap in the terms. So here’s a summary.
Different types of lenses are defined, in part, by their focal length, which determines field of view. “Field of view” means how wide the view is that the lens takes in, and it’s technically measured as an angle in degrees. So a lens that takes in a very wide field of view is called a wide-angle lens. That much is pretty straightforward. The question is, how wide is “wide”?
A lens that provides about the same field of view that humans naturally see is called “normal”. That can vary, depending on the size of the camera’s sensor. In practice, on a camera with a crop sensor, anything in the neighborhood of 35mm might be called a normal lens, while on a full sensor camera, normal would be around 50mm. If you’re not sure whether your camera model has a crop or full sensor, check the camera manual. Most entry level, lower-cost DSLR cameras have a crop sensor.
Focal lengths that present a field of view wider than normal would be considered “wide”. Common focal lengths for wide angle are 18mm, 22mm, and 24mm, with the “wideness” decreasing as the focal length increases and approaches normal. Lenses with focal lengths above normal are called “telephoto”*, a range that generally starts around 75mm and extends up from there. General consumer-market lenses usually top out at around 600mm or a bit more; after that, you get into specialized lenses that get very expensive.
*For technical jargon nit-pickers: the term “telephoto” is not necessarily accurate for a lens just because it has a long focal length and narrow field of view. The term “long-focus” lens is more technically inclusive, because “telephoto” really means that the focal length of the lens is longer than the physical length. So a lens that has a 500mm focal length, but is physically 500mm long, is to a purist not technically “telephoto”, but is “long-focus”. However, in common use, you’ll hear any long lens called telephoto, so just let it slide.
A “prime” lens is one with a single, specific, fixed focal length. (They’re also sometimes called “fixed” lenses; the terms “prime” and “fixed” mean the same thing here.) Having a fixed focal length also means they have a fixed field of view. Common prime lenses can be wide (18mm, 24mm), normal (50mm), short or medium telephoto (75mm, 105mm), or long telephoto (200mm and up).
Zoom lenses are the ones that have variable focal lengths. Some can be wide angle at their short end, and then zoom in to telephoto at their longer end. If you just bought a DSLR camera with a lens included (a “kit”), the included kit lens is almost certainly a zoom, and not a prime lens. These are the most common lenses used by hobby photographers, and perhaps also by professionals nowadays, because they offer such convenience. You can be shooting landscapes at a wide angle one minute, and then zoom in to shoot a close-up of a flower or bird the next, without having to change lenses.
So if zoom lenses are so versatile, why aren’t they used all the time? Well, they certainly are used a lot of the time. But one drawback of zoom lenses is that as they zoom, stuff has to move inside them: the reason they can change focal length is that the different glass elements inside can move back and forth with respect to each other. But all that movement comes at a price: they aren’t able to focus as sharply, they often cost more, and they’re subject to more aberration than prime lenses, which have glass elements that don’t have to move around. They also don’t usually have as large an aperture (or low f-stop) as prime lenses, and so don’t perform as well in low light.
Prime lenses are often cheaper, and usually provide sharper images with less aberration, along with larger apertures that make them better in low light. The drawback to them is that you have to be able to get closer or farther from your subject in order to “zoom” (a process known as “zooming with your feet”). There’s nothing wrong with that, if you can do it. But getting close to an animal in the wild isn’t always easy, and walking back away from your subject can be tough if you run out of room to back up. So prime lenses generally give better quality images, but aren’t as versatile as zoom lenses.
Both prime and zoom lenses have their advantages, and neither is automatically a better choice. But if you start to get serious about photography, you’ll almost certainly want to have one or more of each type in your gear. For shooting great landscape shots, I love a prime lens, usually either wide angle or normal. For shooting wildlife and birds that don’t like to let me get close, a long telephoto zoom is the way to go. For a general walk-around lens, where you’re not too sure what you might want to shoot next, a zoom that ranges from wide to short-telephoto (such as the common 18mm – 105mm kit lenses) is often a good choice. The whole point of a camera with interchangeable lenses is that you can use different lenses for different purposes.
Another kind of lens you’ll hear or read about is “macro”. A macro lens, in common parlance, is a lens that lets you get in very close to your subject; it has a very close focusing distance.* All lenses have a minimum focus distance (which you’ll find listed in the lens specifications); anything closer than that, and they go cross-eyed and can’t focus. To see this, put your usual shooting lens on your camera and then try to focus on your own hand, just a few inches from the lens. You won’t be able to get that close and get the lens to focus; you probably have to be a foot away or so. But with a macro lens, you can focus on subjects much closer. Macro lenses are used for taking extreme close-ups of insects and flowers and things like that.
*Again, for the technically picky, the true definition of a macro lens has to do with the size of the subject’s image on the camera’s sensor, in relation to the actual physical size of the subject. But in practical terms, and as “macro lens” is commonly used, it’s a lens that is able to get really close and still focus, and thereby take close-up photos of the subject.
You may also hear the term “fast” used for some lenses. This simply means that their aperture can be opened up quite wide (f/2 or wider), which lets in a lot more light, and which therefore allows shooting in low light conditions. Fast lenses are nearly always prime lenses, at least in the general consumer price range.
Notice that I just used the word “wide” in the previous paragraph to refer to the aperture of a lens, rather than the field of view. This is another source of confusion, because sometimes when someone says “wide” it might not be immediately clear whether they mean “wide open aperture” or “wide-angle field of view”. These two different uses have nothing to do with each other: a wide angle lens can be used with a narrow aperture, and a telephoto lens can be used with a wide aperture. Don’t let it throw you; you’ll get used it.
Shot with a Nikon 18-105mm zoom lens, zoomed out to 22mm (wide angle).
Shot with the same 18-105mm zoom lens, zoomed in to 105mm (medium telephoto).
A macro shot, with a 105mm prime macro lens, very close to the teasels.