What are DSLR telephoto lenses?
DSLR lenses come in several types and each one of them offers unique functionality. Telephoto lenses are usually used when the photographer can’t or shouldn’t get too near to the subject for various different reasons. Telephoto lenses are useful especially for the purpose of enlarging distant subjects. It is also known to produce a shallow field of depth and it can deplete the obvious distance between the objects in the foreground and at the background. It is applicable for several different types of photography such as sports, wildlife, portraits, macro and sometimes, even landscape photography.
Overview on DSLR telephoto lenses
A telephoto lens usually has a focal length longer than the standard lens which is 50 mm. It magnifies its subject several factor up depending on the mm specification of the lens. For example, a 200mm lens has a focal length that is 4 times higher than the standard 50mm lens. Hence, a subject which is captured by a 200mm telephoto lens will be magnified by a factor of four from its real-life size.
DSLR telephoto lenses come either in prime telephoto lenses (fixed focal length) or zoom telephoto lenses. Prime telephoto lenses provides a higher standard quality of photo and zoom telephoto lenses, on the other hand, offer convenience as photographers may adjust the zoom-in and zoom-out settings as they please.
The focal length of telephoto lenses usually starts somewhere around 85mm and it can go up to 800mm and higher. The cost of the lens goes up together with the length and it also gets bulkier and heavier. There are three groups of telephoto lenses such as:
- Short telephoto lenses – 85mm – 135mm, suitable for portraits
- Medium telephoto lenses – 135mm – 300mm, suitable for sports and wildlife
- Super telephoto lenses – 300mm and above, suitable for far sports, wildlife, landscapes and astrophotography
Telephoto depth of field and aperture
Since telephoto lenses have longer focal length compared to normal lenses, it usually produces a smaller depth of field, which directly translated to blurriness of the background and foreground image. As the telephoto lenses get longer, it gets harder to focus on the subject. Therefore, to avoid blurriness in the photo, there must be wide enough aperture that can assist the lens to achieve a fast shutter speed. However, it is also important to note that as the focal length gets longer and the aperture gets wider, the lens get more and more expensive.
Perspective of telephoto
DSLR telephoto lenses are known to produce a visual effect known as foreshortening. Due to the shallow depth of field, telephoto lenses often make objects in the image to appear very close to each other, way closer than they are in the real life. The images can also appear to be in 2-dimensional view because of the absence of distant between the objects. This foreshortening is helpful for photographers who wish to increase the manifestation of compression or congestion in the photo. Another effect caused by telephoto lenses can be seen in the size of the distant objects as they can look somewhat enlarged. This can be quite helpful for those who want to capture and emphasis the background object. For example, the photographer might want to focus on a majestic mountain or the beautiful full moon which is usually located in the background.
Extra accessories of telephoto lenses
Super telephoto lenses are prone to camera shake. The shallow depth of field makes the focusing more difficult and telephoto lenses with minimum aperture may have slow shutter speeds and are exposed to the shakiness of the hands. Therefore, it is quite impossible to shoot using telephoto lenses without seeing the blurry effect, unless the lenses come with Optical Stabilization (OS) feature. Hence, a camera tripod or monopod is usually required during the shooting in order to attain sharp and blur-free images. The telephoto lenses are also bulkier and heavier than the normal lenses. Monopod and tripod can definitely help to carry the weight and lift off some of the strains from the arms.
When to use telephoto lenses?
1) When you want to capture, enlarge and emphasize the distant object
2) When you want to capture fast sports actions or moving wildlife
3) When you want to capture a macro image of animals without wanting to get too close to the animal and disturb them or make them run away
4) When you want to shoot for portrait photography
5) When you want to shoot landscape and produce different perspectives (e.g. frame-filling shots)
Here, we are sharing with you a video that further explains how to use telephoto lenses on your digital SLR. Have a look at the video below.