Photography - Knowledge

Photography Basics: Beginner's Guide to Choose the Best DSLR Lenses

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Being completely new to photography, all the different kinds of lenses, cameras and their uses might have left you entirely baffled. You might be wondering what do all the numbers, symbols and letters on your DSLR lenses mean. Also, as there are so many lenses available, what is the use of each one? What do terms like aperture and focal length mean? What’s the deal with those interchangeable lenses? Which one should you be purchasing? So many questions and undoubtedly all of them might be making you anxious. Here, we would be answering all those questions for you so that you can purchase what’s best for you and grow successfully as a photographer. 

Understanding the Setting on DSLR Lenses

First, let’s take a look at all the terms that are used generally in the context of lenses. 

The Focal Length 

The focal length is the primary characteristic of any lens. It is defined as the total distance between the optical centre of the lens and the image sensor when it is focused at infinity. But, what is an optical centre? The optical centre of the lens is usually the point within the lens at which the rays of light entering from two different sources are assumed to intersect. 

The longer focal length offers a shorter field of view but offers a greater magnification. On the other hand, the shorter focal length offers a wide field of view but lesser magnification. The DSLR lenses standard measurement for the focal length in millimetres which is generally displayed on the barrel of the lens along with the adaptor ring’s size. 

dslr lenses
The rings that will help your focus and zoom (source)

The Aperture 

The aperture of the camera lens determines the amount of light that the lens transmits to the image sensor. The lower the maximum aperture is, the better the quality of the lens would be in terms of brightness. You would notice that the better quality zoom lenses deliver a constant f-stop throughout the focal range while the in the lower quality lenses, the f-stop varies as you travel up the focal range. In simpler words, this means that the lens with a lower f-number is a better quality lens and would allow you to do more with it. The lenses with a lower f-number are usually brighter which means that you would be able to take better quality pictures in low-light conditions and get a better exposure. In addition to that, these lenses allow you to achieve a very shallow depth of field. Any lens that is f/2.8 or lower is considered to be a professional lens and will have a comparatively higher price tag. 

On the DSLR lenses, when you see a 1: followed by a certain number, it represents the lens’s aperture. In case the number reads 1:1.4, it means that the wide open aperture of the lens is f/1.4. In a few zoom lenses, you might notice two numbers after 1:. For instance, it could be an aperture of 1:3.5-4.5 in a 24-70mm lens. This means that when the lens is zoomed in completely, the widest possible aperture would change from f/3.5 to f/4.5. We hope the camera lens number explanation gave you a clear idea. Let’s now check the lens diameter.

To know about the aperture in detail, read - What is Aperture in Photography

Lens Diameter 

Different lenses have different diameters and by knowing it can be beneficial when you are purchasing lens hoods and filters. The diameter would be displayed on the lens barrel beside the focal length and the aperture. So, if the lens has a diameter of 67mm, it would require a 67mm filter and a 67mm lens hood. 


On the side of your DSLR lenses, you would find the letter AF/MF in Canon lenses or M+A/M in Nikon lenses in a small white line. It would have a switch beneath it. This would allow you to change your lens easily from Autofocus to manual focus. In manual focus mode, you are required to rotate the focus ring on the lens to achieve the correct focus on your subject.  On the other hand, in the autofocus mode, the camera would attempt to focus on the subject for you. 

dslr lenses anatomy
Switch from auto to manual focus with a button (source)


The IS (Image Stabilization-Canon) and VR (Vibration Reduction – Nikon) represents the lens technology which has been designed to minimize the camera shake’s effect. It is to be noted that not all the DSLR lenses come equipped with this technology. If your lens has it, there would be the abbreviation "IS" or "VR" near the glass on the lens. If not, there would be "Image Stabilization" or "Vibration Reduction" marked on the body of the lens.

Different Types of DSLR Lenses 

There are various kinds of lenses available that you can choose from. Let’s have a look at the most popular ones. 

The Kit Lens

The kit lens is way cheaper than purchasing the lenses and the camera body separately. For instance, with most of the consumer-level cameras, you would get the 18-55mm lens which is considered as the perfect lens by the experts for most of the immediate photographic needs. It has a decent wide angle and has the ability to zoom in on objects far away. Wondering how much zoom does 18-55mm lens have then, it zooms out to 18mm that means the maximum aperture is f/3.5 and zooms into 55 mm (f/5.6)

Check - 3 Lenses for a Beginner's Photography Kit

Standard/Normal or Portrait Lens 

The standard or the portrait lens has a fixed focal length and produces results which are fairly similar to what the human eye views in terms of angle of viewing and perspective. For a 35mm film camera or even a full-frame DSLR, the 50mm lens is considered to be standard. At higher focal lengths (85mm or 100mm) you would have an ideal lens for portraits. This is because when coupled with a wide aperture, it softens any background detail. 

As a fast lens, you would be able to shoot in low-lighting conditions. When you keep the aperture wide and get up close to your subject, certain parts of the face would be sharp while the other parts would be blurred softly. If you tighten the aperture a teeny bit, the entire head of the subject would be clear while the background would be softly blurred. 

Check - 35mm vs. 50mm: The Battle of the Lenses

Wide Angle Lens 

The wide-angle lens has a shorter focal length when compared to the portrait lens. With this camera lens, you would be able to capture a wider angle of view. When it comes to shooting outdoor landscapes or group portraits, the wide-angle lens is the most favourable choice. At times these lenses are the only way to capture everything in the frame without excluding any essential elements. 

Check - Canon 85mm 1.8: A High-End Camera Lens at an Affordable Price

Zoom Lens 

The zoom lenses have variable focal lengths and are extremely beneficial. A few zoom lenses can range between the variable focal lengths so that you can enjoy extensive versatility for composition. The focal length of these lenses can be varied as opposed to the fixed focal length. A true zoom lens, also known as a parfocal lens, is the one which maintains focus when the focal length changes. Zoom lenses are often described by the ratio of their longest to shortest focal lengths.

Telephoto Lens 

The telephoto lenses (100mm to 800mm) can offer a narrow field of view. With the help of these long lenses, you would be able to compress the distance and the sense of depth and thereby pick a certain object from far away. With the telephoto lens, you would be able to capture subjects from hundreds of feet away. They have a very strong resolving power and an inherent shallow DOF. Even a slight lateral movement would take the subject out of focus. You might have seen the wildlife photographers using the large telephoto lens. These DSLR Lenses are also used for portraits, sports photography and at times for documentaries. 

Check - All about Outdoor Portrait Photography

telephoto lens
Telephoto lens for wildlife photography

Macro Lens 

The macro lenses are extremely useful when it comes to close-up or “macro” photography. The focal length of the macro lenses ranges between 50-200mm. If you were wondering what does 55-200mm lens mean, then they are medium size telephoto lens with good zoom quality. They are excellent for action based photography such as wildlife, landscape, and sports photography. The great thing about these lenses is the fact that they offer an unbelievably sharp focus for the subjects that are within the macro focus distance. 

However, they tend to lose their ability when it comes to focusing on objects at a distance. In fact to obtain the perfect focus for your subject you can use distance scale for macro photography. How to use distance scale? Check the focusing ring on your camera, you will find markings on it. These markings indicate the distance at which your subject will appear in focus. The marking starts from 1 meter and goes till infinity. For macro, you can set it to a distance depending on your subject and then work around with your shots. These lenses enable the photographer to obtain life-size of subjects like butterflies, wasps, flowers and similar objects. 

Fisheye Lens 

The fisheye lens is a specially designed, wide-angle lens which offers extremely wide images by changing the straight lines into curves. The images that these lenses produce are convex, circular or oval. They distort the perspective and create a 180° image. In a circular fisheye lens, the image circle is inscribed in the sensor area. In a full-frame fisheye lens, the image circle is circumscribed around the sensor area. Different fisheye lenses distort images in a different manner and the way of distortion is known as their mapping function. The focal length’s range varies from 7-16mm in these lenses. 

Know about the fisheye lens in detail. Check - Fisheye Lens Photography: Get Creative With it!

fisheye lens
Fisheye lens to capture the world in unique way

Summing Up 

Now, you must have understood all the basic terms related to the DSLR lenses, you would be able to make the right choice for yourself. As seen above, when it comes to purchasing a lens, there are a lot of possible choices. Each and every lens would give you a different and distinct image. As a photographer, the best lens for you would be dependent on the kind of photography that you are interested in. By choosing the right kind of lens, you would be able to capture the world in a way you see it or wish to present it. 

Now that you know about the DSLR lenses, also know about How to clean your DSLR camera lens - Quick and Easy Way

We really hope that this guide has helped you know more about the lenses. Do you have any questions you want us to answer? If yes, feel free to do so in the comment section below. We would be really happy to answer you!

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