natural choice

What is a prime lens?

We've taken a jump over 'O' and landed directly on 'P' for the next part of the Photography Fundamentals series. Here, we'll be taking a look at prime lenses, what they are, and why you should have one. At least one. In fact, we reckon that until you've got a decent prime lens, you've not really lived, photographically speaking. Here's why.

Define prime

What's a prime lens? For once, it's a simple definition: it's a lens with a fixed focal length. They might be 35mm, 50mm, 85mm, 100mm, whatever, they just don't move. And yes, this can most definitely be a good thing.

A bit of history

Back in the infancy of photography, we never had anything but prime lenses. When you bought a camera body, you also had to buy a camera lens to go with it. A 50mm ƒ/1.8 was pretty much the slowest lens you could buy as a starter kit.

To this day, a 50mm ƒ/1.8 is the cheapest lens you can buy in the entire Canon EF lens arsenal. And if you don’t have one, you’re missing out.

Canon's 50mm ƒ/1.8 - a bargain at under £100

From your first prime, you move on. You might get a faster ‘normal’ prime, like a 50mm ƒ/1.4 or a ƒ/1.2 (or, if you’re intro your retro gear, the incredibly bright Canon 50mm ƒ/0.95. This lens is four times faster than the human eye, and is one of the fastest lenses in the world along with, for example, the lenses available for the Nikon 7 range finders in the early 1950s.)

If you’re into landscapes, a 28mm would be the natural choice. 85mm, 100mm, and 135mm prime lenses became the de facto standard for portrait photography all ’round the world.

Nikon's 85mm ƒ1.8

The first zoom lenses were patented in the early 1900s, and the first commercial production of zoom lenses for stills photography started in the early 1960s. All of a sudden, zoom lenses were all the rage.

Why would you limit yourself to a single focal length, when you can cover a whole range? So, manufacturers shrugged, and started creating zoom lenses.

What’s going on now?

Nowadays, all ‘kit lenses’ (lenses you get bundled with camera bundles) are consumer-grade zoom lenses. My dad recently got suckered into buying an 18-55mm and a 55-200mm lens (after I explicitly told him to buy a Canon 28-135 ƒ/3.5 Image Stabilised lens… Tssk, doesn’t the lad know I run a photography blog, or something?), for example, and he isn’t stupid. It’s just too tempting to get a wider zoom range, in the hope that the increased flexibility will get you the photos you need.

Tamron's 18-270mm offers a huge focal range, but is it as sharp as a prime lens?

The thing is, a zoom range is all good and well, but ultimately, it’s all about sharpness. Are your photos so crisp they jump out of the screen at you? If not, you’re probably doing something wrong. So what happens if I tell you that one of the sharpest lenses a consumer can buy is also the cheapest lens Canon makes? You’d be surprised, right? But it’s the truth. Time and time again, people are amazed when they review consumer-grade zooms against far cheaper prime lenses. But — as Tabaware explores — they aren’t even in the same league.

So why is this? Well, it’s damn simple, really… it’s far easier to mass produce a prime lens: Because it only has to be sharp at one focal length, the optics are a hell of a lot simpler. So they can concentrate on getting it to be really good, rather than just being good enough.

Why should I care?

It really depends, to be honest: What do you want out of your photography? If you are looking for convenience and holiday snaps, by all means, go for the first and best zoom lens. Hell, I've a few of them myself and love to use them, but still, there’s a certain feeling of zen about using prime lenses. They can be slightly limited, sure, but they’re also sharper than a surgeon’s scalpel, cheap as a bag of crisps, and they are just a better idea overall, especially as you are just learning about photography.

Peacock butterfly

So, if you’re in the market for a new camera, and the kit comes with some two-bit zoom lens, see if you can’t convince the salesperson to do you a deal. “So, you want to sell me this lens? How much does it normally cost? Interesting. I can see that you sell a 50mm ƒ/1.8 for less than that. Can you give me one of those instead?” Sure, money-wise, you’ll lose out. But your portfolio will thank you for it for years to come.

Are prime lenses really such a good idea?

Well, yes, I would argue so. I'm a frequent traveller and it isn't unusual for me to get on a plane with just my camera body, a 50mm ƒ/1.4, and Canon PowerShot S95.

Check out the gallery from one of my trips to Vietnam, or a bigger collection of my photos taken with the humble 50mm.

Convinced yet? Good. Head over to your favourite photographic retailer, and buy yourself a lovely little prime. Lazy? Okay then - Canon users, click here. Nikon users, click here. Pentax users, you can click here. Sony users, click here. And Olympus users, click here. You're welcome.

TL;DR

  • Prime lenses are lenses with fixed focal lengths
  • They are usually sharper than zoom lenses because they have fewer moving parts
  • And fewer moving parts also makes them cheaper to manufacture and less likely to suffer from a fault

Noise << Photography Fundamentals >> Quality versus quantity