What is a Telephoto Lens?: Telephoto lenses have a longer focal length and are ideal for bringing distant scenes and subjects closer. Like wide-angle lenses, there are both primes (with fixed focal length) and zooms.
The term “telephoto” is also a general term to denote lenses with a focal length that creates a narrow field of view above 80mm. However, they are divided into three categories:
- Short Tele – Goes from 85mm to 135mm and is great for everyday use as they are compact and light.
- Medium Tele – Bigger, longer and heavier with focal lengths from 135mm to 300mm.
- Super telephoto – with focal lengths over 300mm, this type of telephoto lens offers telescope-like magnification and is too heavy to shoot handheld.
Advantages of a Telephoto Lens
Telezoom, like a 70-200mm, not only makes your main subject appear much larger in the frame. With a telephoto lens, foreground and background elements also appear much closer together. Or rather: the foreground and background are compressed.
Take the giraffe photo below for example. This photo was taken at the Taronga Zoo in Sydney, Australia. What you see in the background is a city across the harbor, which is actually much further away than it appears.
Depth of field of a telephoto zoom lens
Depth of field (DOF) refers to the area of ??an image that appears sharp! It is not a fixed distance, but changes in size depending on the aperture setting and focal length of the lens. Longer lenses create more blur than wide lenses. For example, you will see more blur with a telephoto lens of Sigma zoomed in at a focal length of 200mm than if you set the lens to 18mm.
Use a telephoto lens for nature photography
Wildlife photography is difficult or impossible without telephoto lenses, as animals and birds are easily startled if you get too close. Many sports are impossible to shoot successfully without a telephoto lens because the spectators are far from the action.
Telezoom can produce striking landscape shots, as they allow you to distinguish distant details and ‘flatten’ the perspective.Portrait recording can be improved by blurring the background. This requires a shallow depth of field, a characteristic of telephoto lenses.
To find the minimum safe shutter speed, divide 1 by the focal length used. With a 200mm lens this gives a shutter speed of 1/200 sec. While this works in most cases, there is no absolute guarantee of sharpness and camera shake may still occur at 1/400 sec.
More image stabilization mechanisms
Some telephoto lenses have image stabilization mechanisms that move elements within the lens to counter movement during exposure. These can help you get sharp shots with shutter speeds two to four times slower than normal.
