Here are some of my own personal definitions of focal lengths and lens types in full-frame 35mm photography:
- Fisheye: 6mm, 8mm, 10mm
- Extreme Wide-Angle: 13mm, 15mm, 17mm
- Wide-Angle: 20mm, 21mm, 24mm, 28mm, 35mm
- Normal: 40mm, 50mm, 55mm, 58mm, 60mm
- Portrait (Short) Telephoto: 85mm, 100mm, 105mm, 135mm
- Telephoto: 200mm, 250mm, 300mm
- Long Telephoto/Super Telephoto: 400mm, 600mm, 800mm, 1000mm, 2000mm
- Zoom Lens: 17-24mm, 35-80mm, 24-70mm, 70-150mm, 80-200mm, 150-600mm
- Multi-Use or Normal Range Zoom or Kit Lens: 24-70mm, 28-85mm, 35-105mm
- Macro: Any focal length or zoom with specific correction for very close focus
Zoom simply means that the focal length of the lens is variable. In popular speech, people refer to “zooming in” on something, which is one correct use of the term. It can be confusing to beginner photographers, though.
Simply put, a zoom lens does not always mean telephoto or great magnification. It actually specifically refers to the fact that the focal length can be changed. A lens can be a wide-angle zoom, such as the 17-24mm. Or a telephoto zoom, such as a 70-200mm.
One common lens is a normal range zoom such as a 24-70mm lens, also called a wide to short telezoom or multi-use lens. This is the range most kit lenses are, too.
Prime lenses, or single focal length lenses, are preferred by some photographers over a zoom that has the desired focal length. Reasons include superior image sharpness, faster lens speed, and smaller lens size. Your mileage may vary.
Several manufacturers, including third-party lens makers, have a trio of fast and sharp zoom lenses that can cover a wide variety of photographic situations. Look at examples similar to the 14-24/2.8, 24-70/2.8, and 70-200/2.8 lenses from Sony, Nikon, and Canon. Some photographers will prefer a 16-35/2.8 at the wide end. Fast enough for most uses, very sharp, and heavy duty construction make them a desirable ‘Holy Trinity’ of zoom lenses.
Wide-angle lenses provide a wider field of view compared to a normal lens. This also means that things appear further away due to less magnification.
A wide lens is often used for situations where we want to show more of the scene in front of us in the final image. Some examples are a scenic vista of a rural scene, an interior room for a real estate listing, or a group portrait of an office staff.
You could also use one for a creative look at a subject. Since wide-angle lenses can deliver a very large depth of focus, it opens up subject placement close to the camera while still having the background in focus.