1. Thinking of buying a new lens? Here are 5 important things you need to know first

Thinking of buying a new lens? Here are 5 important things you need to know first


When people look for a new camera, they usually ask about the resolution first. Some consumers think that a camera takes better pictures if it has more megapixels. What they don’t realize is that having a good lens makes all the difference in picture quality.

Photo by Hermes Rivera

The lens is responsible for transferring the image onto the sensor, and if it doesn’t provide a crystal-clear representation of the image, the picture is going to be hazy regardless of the camera sensor’s resolution.

Most kit lenses that come with new cameras these days are good enough for general use. However, if you want to delve deeper into photography, you might want to get lenses that fit your photography style better.

That brings us to the question: What lens should you get next? Before you look around, here are 5 important things you need to know.

01. The basics

To be able to distinguish between a good lens and a poor lens, you need to know a bit about how lenses work. Here are some of the basics:

Focal length is the distance between the lens and the sensor where the image comes into focus. The focal length information is commonly found on the lens body, marked in millimeters (35mm, 50mm, 18-55mm, etc.).

Photo by Chad Verzosa

Aperture is the amount of opening in the lens where the light passes through. The wider the aperture size, the more light reaches the camera.

F-stop refers to the aperture size. High F-stops (small aperture sizes from f/11, f/16, f/22, etc.) let in small amounts of light, while low F-stops (wide aperture sizes from f/1.4, f/1.8, F/2, etc.) let more light in.

Photo by Chad Verzosa

Depth of field is the focusing range where the subject remains sharp. A wide aperture such as f/1.8 has a shallow depth of field, which means that it can separate your subject from the foreground and the background. As the aperture size gets smaller, the deeper the depth of field gets and the sharper everything in the scene looks.

Maximum aperture refers to the lens’ widest aperture size. A lens with a maximum aperture of f/1.2 or f/1.4 is called a fast lens because it lets more light in, allowing for quicker exposure times.

Lens mount is the part of the lens that attaches to the camera. Camera companies offer various lens mounts for different cameras they manufacture. Not every lens is compatible with every camera.

Image sensor format refers to the size of your camera’s sensor. There are many formats available in the market, but the three main ones are:

  • Full-frame format has the same sensor size as a regular 35mm film and is intended for professional use.
  • APS-C format is slightly smaller and is used in most consumer digital SLR cameras.
  • Micro four thirds format has a size the fraction of full-frame and APS-C and is used in smaller cameras.

02. The crop factor

Lenses from full-frame cameras can also be used for crop sensor cameras (as long as they have compatible lens mounts). However, due to the difference in sensor sizes, the equivalent focal length of the lens changes as well. The crop factor is the ratio of the dimensions of a particular crop sensor compared to a 35mm full-frame sensor.

Photo by Chad Verzosa

To find out your camera’s crop factor, multiply the lens’ actual focal length by 1.5 for Nikon or 1.6 for Canon (the two most common brands) to find out its equivalent focal length for the APS-C sensor. For instance, when a 50mm full-frame lens is attached to an APS-C camera, its equivalent focal length increases to 75mm or 80mm.

For other crop sensor sizes, you can use a crop factor calculator to measure your camera's crop factor accurately. Remember that calculating the crop factor is not necessary if you’re using lenses meant for APS-C or other crop-frame cameras; a 50mm APS-C lens has the same focal length when used on an APS-C camera. Crop factor is only required when a full-frame lens is used on a crop frame camera.

03. The difference between a prime lens vs. a zoom lens

Photo by Oli Dale

There are two main types of lenses available for cameras with interchangeable lenses: the prime lens and the zoom lens. Both have pros and cons, and people have their own preferences regarding which lens to use.

A zoom lens comes with most consumer cameras you can buy today. This lens has various focal lengths (kit lenses typically have 18-55mm focal range), which means it can take photographs from up close to really far. Some photographers love it because it can be used in almost any situation. However, the pictures it produces are normally not as crisp as a prime lens.

Photo by Alan Levine

A prime lens has a fixed focal length (24mm, 35mm, 50mm, etc.), which means that it can’t be used for zooming in. It requires more work for the photographer, but the quality of the images that it produces outweigh that of zoom lenses. Also, a prime lens has a wider aperture than most zoom lenses, making it perfect for shooting in dim light.

Photo by FEWhite

04. The different types of lenses

a. Ultra-Wide Lens

An ultra-wide lens has a focal length that is shorter than the height of the camera sensor. For a full-frame sensor (35mm x 24mm), any lens that has a focal length that’s shorter than 24mm is considered an ultra-wide lens. Meanwhile, any lens shorter than 15mm is regarded as an ultra-wide lens for the smaller APS-C sensor. The standard focal lengths found in most ultra wide lenses include 21, 20, 18, and 14mm.

Photo by R. Nial Bradshaw

The ultra-wide lens’ short focal length gives it an unusually wide visual angle, making it perfect for shooting close-ups and panoramas. There are two types of ultra wide lenses available: the curvilinear lens and the rectilinear lens. Although they both have wide visual angles, the curvilinear lens makes the photos look round and slightly distorted around the edges, while the rectilinear lens keeps the image proportional.

Photo by Patrick S.

Typical uses for ultra-wide lenses include landscape photography because of its wide visual angle; architecture photography not only because of its visual coverage but also because it's great for taking photos of both small spaces and large structures; and extreme sports photography because it can be used to capture close-ups of athletes while doing stunts.

Photo by Chris Pizzitola

b. Wide Angle Lens

Just like the ultra-wide lens, the wide lens also has a focal length that is shorter than the camera sensor. The main difference is that it covers less ground than the ultra-wide lens. The typical focal lengths for wide angle lenses are 35, 28, and 24mm.

Photo by Jakob Owens

The wide lens’ broad visual angle makes it perfect for shooting in tighter spaces that regular lenses couldn’t capture. At the same time, it doesn’t suffer from overly distorted images that some ultra-wide lenses are prone to produce.

Photo by Hijanisch

Typical uses for wide angle lenses include landscape and architecture photography, again, because of its visual coverage.

c. Standard Lens

Before zoom kit lenses became popular, most cameras back in the day came with a standard lens. Standard lens is categorized as a prime lens because it has a fixed focal length. The focal lengths typical of full-frame standard lenses include 40mm, 50mm, and 58mm. For APS-C, 28mm and 30mm are considered standard.

Photo by Plus Ultra

A standard lens provides a visual perspective equivalent to what the human eye sees, making it very popular among serious photographers. And because it’s a prime lens, it also provides superior quality image as compared to zoom lenses.

This is the best lens for general use because of its versatility and excellent image quality. Nonetheless, other typical uses for standard lenses include street/documentary photography because its field of view is equivalent to the human eye; travel photography because of the natural look it provides; and portrait photography because it doesn't distort faces and bodies.

Photo by Mark Hodson

d. Telephoto Lens

A telephoto lens is used to magnify scenes that are too far away for regular lenses. For full- frame cameras, lenses with focal lengths between 67mm and 206mm fall under the category of medium telephoto, used for magnifying objects that aren’t very far away. On the other hand, lenses with a focal length of 300mm or more is called a super telephoto, used to photograph subjects from great distances. For APS-C cameras, the crop factor for a medium telephoto begins at 84.3mm, and 300mm for a super telephoto.Many zoom lenses also have medium to super telephoto capabilities. Depending on the manufacturer, some lenses can zoom in from 18mm (wide angle) to 140mm or even 300mm (super telephoto).

Photo by Jay Wennington

Instead of buying APS-C specific telephoto lenses, many photographers like to use lenses from full frame cameras on their APS-C camera to increase magnification. Due to APS-C’s small sensor, any full-frame lens used on an APS-C camera magnifies the image considerably because of the crop factor.

Photo by Bernd Thaller

Typical uses include sports, travel, and wildlife photography, where photographers couldn’t physically get closer to their subject.

Photo by Yeti-legs

e. Macro Lens

A macro lens is a unique lens used for taking photographs of small objects at exceptionally close distances. Apart from regular macro lenses, various attachments such as extension tubes, bellows, and reversed lenses can also be connected to conventional lenses to create macro photographs. The focal lengths of these lenses range from 28mm to 200mm.

Photo by Dennis van Zuljekom

Macro photography is often confused with photomicrography which is taking photographs of small objects with a microscope. Macro photography is the practice of taking images of small objects that can be seen by the naked eye, but not on a microscopic level.

Photo by Sue Corbisez

Typical uses for macro lenses naturephotography because it can capture very small animals and insects at close distances.

05. The lens you really need

Now that you know all the general types of lenses available for you, the question is: Which lens do you really need?

Photo by Annie Spratt

It depends on the type of photography that you want to prioritize. Many photographers have a wide angle lens, a standard lens, and a zoom lens in their camera bag. These three lenses cover most shooting situations from shooting close-ups to photographing faraway subjects.

There are many ways to go about finding the right lenses, and people have their own opinions on which lenses are truly necessary. However, it's never a bad idea to get lenses that would cover a wide range of focal lengths without a lot of gap in between. For instance, you can buy a wide-angle 17mm to 50mm zoom lens, then a 50mm standard lens, and finally 55mm to 300mm zoom telephoto.

Alternatively, you can skip buying the wide-angle lens altogether and get an 18mm to 300mm zoom lens, instead. Just be aware that focal lengths of different zoom lenses varies slightly from manufacturer to manufacturer. For example, Tamron offers 18mm to 400mm, Canon 18mm to 200mm, while Nikon and Sigma both produce 18mm to 300mm lenses.

Realistically, you can’t buy all 3 lenses at once. So if there’s one lens that you have to get now, it would have to be a standard lens. Your kit lens is a zoom lens which you already know how to use. Getting a standard lens will teach you how to take photographs without relying on the convenience of zoom. Once you try it, you’ll be surprised at how easy it is to use, and how crisp your pictures look.

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