How Many Camera Lenses Do You Need? | A Photog's 2021 Guide

Last Updated: February 7, 2019

If you’re the typical photography enthusiast with a serious gear habit, you probably have more than one lens in your sling bag. How many lenses do you need? There’s no shame in saying it – just one more.

But which one, and why? That’s our topic for this tips article, designed to help you figure out where you should next spend your money. Understanding the questions to ponder before you buy will help you make a more satisfying and effective decision.

Let’s go through a quick tour of your lens choices. We will explore why you might find one better than another. We’ll cover prime versus zoom, standard or norm, wide angle, telephoto, and art lenses.

Our discussion focuses on lens choices for DSLR bodies. However, the same criteria for selection apply to other camera formats.

What came with my camera body?

Most of us buy our first serious camera with a lens, either for a specific purpose or as part of a kit. For example, a Nikon D7500 camera kit might come with an AF-P 18-55mm f/3.5-5.6G VR lens and an AF-P 70-300mm f/4.5-6.3G VR lens. EF-S 18-55mm f/3.5-5.6 IS STM, and EF-S 55-250mm f/4-5.6 IS STM lenses accompany the Canon EOS 80D camera.

You’ll see a common thread in the usual pairings. A lens range that errs on the side of wide angle plus a telephoto with enough power to make it obvious the distant lions are yawning on the Serengeti cover the general bases most of us need. What if, though, you want more?

A focal length range of 18-55mm serves the wide-angle needs most of us have. A 70-300mm or 55-250mm can cover portraiture through telephoto work. You will note, however, that all of these lenses have a higher-numbered aperture (f-stop). That means they won’t work as well in low light conditions.

What aperture is best for the shots I like to take?

If you shoot in low light situations, you’ll want a fast lens. This means you want something at f/2.8 or a lower number. (The terminology doesn’t seem logical in these labels, so I’ll state it another way.)

In simplified terms, aperture refers to the width of the opening, allowing light to hit the sensor. That translates the image into your digital (or film) file. While we read the number as f/#, it translates into a fraction, 1/#. An f-stop of 2.0 (1 over 2, or a half) is larger than f/4.0 (1 over 4, or a quarter). Therefore, it is faster.

Some pros will tell you that having a fixed aperture is better than a variable (f-stop with a range) because not adjusting within the range while changing the aperture in your DSLR camera settings eliminates a possibility for error. On the other hand, it also limits fine tuning you might want in framing and calibrating the shot. A Canon EF 100-300mm f/4.5-5.6 USM at the 100mm end of its focal range will never capture as much light as a Canon EF 100mm f/2.0 USM.

Should I buy prime or zoom lenses?

The focal length debate is equally laced with opposing views. In years past, it was said that prime lenses were better with superior optics and studier builds. That is, arguably, no longer the case.

If you buy a prime, however, know that it’s generally a single-purpose. You might be changing lenses on your camera body or using multiple body/lens combos. You may need to do that to meet your range of photography needs.

A slower zoom like a Nikon 1 Nikkor VR 70-300mm f/4.5-5.6 gives you incredible flexibility for everything from those soft bokeh close-ups to landscape panoramas. Middle distance telephoto street shots will be your usual use for a prime like the Nikon AF Nikkor 135mm f/2D DC. Primes are terrific for things like portraiture, where you’re almost always shooting at a particular focal length (single individual or group shots).

A fast zoom lens is great for action and sports. The Nikon 80-200mm f/2.8D ED AF and Canon EF 70-200mm f/2.8L USM are favorites of the professionals, as is the Sigma 70-200mm f/2.8 EX DG OS HSM if it is available in a mount that works on your body. In primes, Canon EF 400mm f/2.8L IS II USM and Nikon 300mm f/2.8 G ED-IF II AF-S VR-II are pro-level (albeit pricey) alternatives.

Why does sensor size matter in my lens choice?

The sensor captures the image, with full frame being the equivalent of 35mm film. The most common smaller (or cropped) sensor is APS. For anything other than a full frame camera, you need to calculate the equivalent focal length. (For more on what this means, check out the tips article on your camera’s sensor size and why it matters.)

Do you want to achieve the same effect, such as wide angle? You’ll need to adjust the equivalent focal length lens you are going to buy. That is the case if you have an APS-C or -H camera.

Usually we multiply the lens and the crop factor. Here we’re dividing the two numbers. That way, you know what focal length lens you need to buy to achieve the look you want in your images.

Let’s use a couple of camera examples, a Nikon D500 and a Canon EOS Rebel T71, both APS-C sensor-sized bodies with a crop factor of 1.6. If you want to achieve a wide angle capability of 35mm with these bodies, you divide 35 by 1.6. That means you need a lens with a focal length of approximately 22mm to shoot with that basic wide angle capability.

When is a lens wide-angle, or telephoto, or whatever?

Here’s a handy chart with what are generally accepted to be the focal lengths in full frame and the most popular alternative sensor size, APS-C. The focal length indicates the typical name, followed by what that lens is called in full frame (that’s how all lenses are labeled). If you’re shooting an APS-C camera, you’ll need to buy a lens labeled with the focal length in our third column to achieve the same effect.

*Name of focal length*	*Range in mm for full frame (also lens label)*	*Equivalent mm you need to buy for APS-C*	*Best used for*
Ultra wide angle	24mm or shorter	15mm or shorter	Architecture, macros
Wide angle	25-43mm	16-27mm	Landscapes
“Nifty-fifty”	50mm	31mm	Common general purpose
Standard (or normal)	35-70mm	22-44mm	Daily or street work
Portrait	85-135mm	53-84mm	Portraits, food, near-in close-ups
Medium telephoto	70-135mm	44-84mm	Documentary
Ultra telephoto	135mm or longer	84mm or longer	Fast action, sports, distance close-ups

In other words, if you want a lens that’s good for portraits on that Nikon APS-C sensor, you’ll be looking for something like the Nikon AF Micro-Nikkor 60mm f/2.8D. Using the Canon APS-C to shoot sports on a large outdoor playing field, you could buy the Canon EF 100-400mm f/4.5-5.6L IS II USM and enjoy plenty of range flexibility.

Did you figure out the happy coincidence yet? That zoom lens that came in your kit, either at the wide end of the spectrum or the telephoto, might be capable of more than you think. It’s up to us as photogs to figure out how to advance our skills to achieve those perfect shots.

Are art lenses just for special effects?

Art lenses are for special effects, distortions, and so much more. Consider how difficult it might be to capture a photo of something smaller than your sensor or show off those super-straight building lines. How close can you get in physical space, and how much do you need to zoom in even more to get the image of your dreams?

The Sigma 105mm f/2.8 EX DG Macro comes with mounts that work on Canon, Nikon, Pentax, Sony and other bodies. Its focus will remain as close as a foot from your subject. Zooming in with this kind of lens allows you to see the fine details on a bug the size of a crumb with clarity and depth, making the bug bigger than the sensor, or the ‘macro’ effect.

Another popular artsy lens is a fisheye, such as the Nikon AF Fisheye-Nikkor 16mm f/2.8D. This type of lens is curved, like a fish’s eye, and creates a commanding distortion at the corners of your image – and in the middle. Other arts lenses are made to create waves or other misshapes, great to use if you want a building with a structure of straight lines to look like the ocean.

Overwhelmed – what should I buy next?

I understand your feeling, because I have it myself each time I think about what additional lenses I want. I make my decision by answering these questions:

What lenses do I already have that shoot acceptable quality work?
What’s missing in my range of focal lengths and apertures, based on what I like to shoot?
How much flexibility do I want, prime versus zoom?
Do I need any particular features, like image stabilization or weather resistance?
How will I use the shots, meaning do I need to buy professional ($$$) quality optics?
What can I afford?

If you rarely shoot a portrait but love to capture images of butterflies, you might want a faster, longer lens so you can get up close and personal with the creatures. Going for artsy shots you want to sell as posters? Buy the best glass you can afford (which may not be the lens that costs the most) so enlargements have the level of detail needed for the final size.

If you don’t yet know what you want to do, practice – a lot – with the lenses you already have, then visit back here and take a look at our comparisons on specific focal length categories of lenses for more detailed advice.