Which Lens Should I Buy for My DSLR Camera?

Photography Tips

One of the most important advantages of DSLR cameras is the ability to use different lenses. However deciding on which lens to buy and which lens is suitable for a specific type of photography is a bit difficult. In this article we learn about the advantages and the main purposes of specific types of lenses. Let’s have a look at different types of lenses and learn when they are used.

Prime Lenses and Zoom Lenses

A lens with a fixed focal length is called a prime lens. As the focal length is fixed, in order to compose a photo you will need to adjust your distance to the scene to have specific objects or people in the photo. With zoom lenses, you use the zoom level to compose the photo instead of changing the distance of the camera to the scene.

Prime lenses have a more simple build than zoom lenses and they can be designed to have very much better performance, sharpness and quality than zoom lenses. Zoom lenses normally show different types of errors in different focal lengths while prime lenses have fewer such errors. Prime lenses are compact and much smaller than zoom lenses. Their price is also cheaper than zoom lenses in an equal aperture size. You can buy a 50mm f/1.8 lens for a Canon or Nikon camera for around $100 while a zoom lens with the same aperture size might cost above $1000.

Normal Prime Lens

A prime lens (i.e. with a fixed focal point) with a focal length of 50mm is called a normal lens. Photos taken with a 50mm lens seem similar to what our eyes see at the scene (perspective, angles, etc). Canon, Nikon, and some other DSLR brands, sell normal lenses with an f/1.8 aperture size or better at a cheap price. An f/1.8 normal lens is suitable for relatively low light conditions and produces sharp, bright photos.

Short Zoom Lenses

Zoom lenses which cover the range of up to 50–60mm can be considered in this category. Examples of these lenses are 35–70mm f/3.4-4.5 and 28–70mm f/3.5-4.5 lenses. Nowadays some Canon and Nikon models are offered with a cheap 18–55mm f/3.5-4.5 lens. These lenses are considered short zoom lenses, while they also cover wide and super wide range.

Super Zoom Lenses

These are the types which cover a super big range. Super zoom lenses, like a 18–200mm lens, cover wide-angle as well as tele-focal lengths.

However the most imporant feature of these lenses is their convenience (avoiding lens change). These lenses can offer almost every focal length you need and therefore they are sometimes called walk around lenses. If convenience is not a factor, we recommend you to use more than one lens with better performance in smaller focal length ranges.

Aperture Size

Bigger aperture sizes (i.e. smaller f number) like f/1.4, f/1.8, and f/2 provide more light to the camera sensor and therefore are faster lenses (photo can be taken in a faster shutter time). However zoom lenses with bigger aperture sizes might be unbelievably expensive. The f number is calculated by dividing the focal length by the aperture diameter. As an example, if the aperture size (i.e. diaphragm window) of a 50mm lens is set to 6.25mm the f number will be 50mm/6.25mm = 8, meaning that with this aperture size, lens has been set to f/8.

Wide-angle and Ultra Wide-Angle Lenses

Lenses with a focal length of 21mm to 35mm are normally called wide-angle lenses. Lenses with a focal length of less than 21mm are called ultra wide-angle lenses. These lenses can be either prime lenses or varying focal length ones (zoom lenses). Wide-angle prime lenses have better aperture sizes (in the range of f/1.4 to f/2.8) than wide-angle zoom lenses (aperture sizes of f/3.5-f/4.5 most of the time). Again the zoom types provide flexibility while prime lenses provide sharper photos, lower prices, and bigger aperture sizes (i.e. better photos in low light conditions). There are also zoom lenses which just cover wide and super wide ranges. These include 21–35mm and 18–28mm lenses.

The large coverage angle is also one of the benefits of wide and super wide lenses. An ultra wide lens can sometimes capture up to a 90 degree angle or even more.

Wide and ultra wide lenses normally have perspective distortion. This kind of distortion causes nearby objects to be appear much larger than far away objects. These lenses are suitable for taking photos inside buildings, street photography, and so on.

If you mostly shoot inside buildings, a lens covering focal lengths of 28mm or below will be suitable. This kind of lens allows you to capture a considerable angle of a scene without the need to have a big distance from the subject. However, if you shoot portraits and nature, a longer range lens will be more useful. In these cases, a 35–135mm lens is a good choice.

Long Telephoto Lenses

Lenses with a focal length of 135mm or above are normally considered long telephoto lenses. Tele lenses which have varying focal lengths are called telephoto zoom lenses, while those with a fixed focal length are simply called telephoto lenses. You can easily find 55–200mm, 55-250mm, 70–300mm, and similar telephoto zoom lenses for most of the DSLR brands. However because of the big range of the lenses and complicated design, different focal lengths of the lenses might show different errors and quality. These lenses normally have a lower performance than short zoom lenses and fixed focal length telephoto lenses. A 200mm telephoto prime lens is an example of non-zoom telephoto lens.

Medium Telephoto Lenses

Lenses with focal length of the range 85–135mm are sometimes referred as portrait lenses. This is because their perspective distortion is low, and a suitable distance between the subject person and camera can be maintained. Many telephoto zoom lenses can be used in this range, but they are heavier, bigger and their maximum aperture size is smaller than prime lenses. However if you shoot a lot of portraits, medium prime telephoto lenses with a focal length of between 85mm and 105mm would be more suitable.

Prime medium telephoto lenses have less perspective error and as mentioned earlier their image quality is sharper and brighter, and bigger aperture size prime lenses are cheaper than zoom lenses with the same maximum aperture size.

Macro Lenses

Macro lenses are designed to provide a very high level of magnification and also very short focusing distances. In normal zoom lenses, the minimum focus distance (i.e. the distance between lens and the object) is normally larger than 30 centimeters. This distance is a few centimeters for macro lenses so you can take photos from a shorter distance and have a sharp and very detailed photo of a very small object (like a small flower or a bee).

About the Author:
Mac Sarmady writes for Society50. The Photography Club of Society50 has a Q&A section for photography issues.