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What is a prime lens? Here’s why you need one in your camera bag

Nikkor Z 50mm f/1.8 S
Hillary Grigonis/Digital Trends

If you’re new to the world of photography, the idea of a lens that doesn’t zoom might seem a bit odd. Even our phones have zoom lenses on them now, or a least a version of zoom thanks to multiple lenses and digital tricks. And yet, some of the best lenses for DSLRs and mirrorless cameras have no zoom at all. While sometimes cheap, these “prime” lenses can go on to cost thousands of dollars. So what makes such a seemingly basic lens so valuable?

What is a prime lens?

A prime lens is simply a lens that doesn’t zoom. It gives you one angle of view, and that’s it. Fixed to a single focal length, such a lens may sound like a disadvantage, and while that would be true in some situations, primes can also offer numerous advantages.

As prime lenses don’t need the moving parts and extra glass required for a lens to zoom in and out, they can focus on other features. First and foremost, prime lenses often have a wider, or “faster,” maximum aperture. The aperture controls how much light enters the camera, and more light means better low light performance, faster shutter speeds, and more. Professional zoom lenses often have relatively fast f/2.8 apertures — and prices well within the four-figure range — but even the cheapest 50mm primes lenses can get you to f/1.8, which is over twice the light-gathering capability, sometimes for less than $200.

The aperture also controls the depth of field, or the amount of the photo that is in focus. The wider aperture of a prime lens will naturally create that out-of-focus background blur that makes portraits pop and which smartphone manufacturers work very hard to emulate digitally.

Without the complexities of a zoom, prime lenses are often sharper, as well. A very cheap prime lens won’t necessarily outclass an expensive zoom, but a $200 prime will almost assuredly be sharper than the $200 kit lens that comes on many DSLRs or mirrorless cameras. Likewise, primes costing in the thousands of dollars are revered by professionals for their sharpness compared to high-end zooms — the $4,895 Hasselblad XCD 80mm f/1.9 is a good example of this.

Besides the image quality, using a prime lens simply means a much lighter, more compact lens. Pancake lenses are the most extreme example of this, where a lens is shorter than it is wide. This makes primes a great choice for lightweight mirrorless systems. Of course, primes aren’t always lightweights — the Sigma 105mm f/1.4, for example, is a beast of a lens at 3.6 pounds. It’s also worth noting that buying one 24-70mm zoom is going to be more compact, overall, than buying several different prime lenses to fill in that same focal length range. But if you’re looking for a compact one-lens solution, a prime is often the best way to go.

We’ve seen a push toward higher-end prime lenses in recent years as camera companies compete to attract professional customers, but you can still find affordable primes for many systems. For DSLR shooters, Canon’s basic EF 50mm f/1.8 is only $125, while Nikon’s AF-S 50mm f/1.8 is about $216. Keep in mind that newer mirrorless systems are usually not quite so affordable.

Disadvantages of prime lenses

Prime lenses have a lot to love — but that doesn’t mean a fixed focal length lens is right for everyone or every situation. First, zoom lenses are often a must to capturing action and events without missing the moment because you are too busy swapping lenses. Zoom lenses tend to have a big advantage for sports and events, while prime lenses tend to have more to love in genres that allow for enough time to “zoom with your feet” or swap to a different lens, such as portraits and landscapes.

While zoom lenses may be lighter and cheaper, you’d have to invest in more lenses to cover the same range. While you can easily buy two prime lenses to cover the most important focal lengths of a zoom, if you absolutely need to cover every possible focal length in that range, you’ll be adding more weight to your bag and spending more money than simply opting for the zoom.

The best prime lenses for upgrading from a kit lens

Olympus M.Zuiko 45mm F1.2 Pro review
Daven Mathies/Digital Trends

If you are shooting a mirrorless or DSLR camera with the kit lens that came with the camera, a prime lens offers a serious boost in image quality without a big investment. Here are some of the best prime lenses at a few favorite focal lengths for different camera systems. These are categorized by their full-frame equivalent focal lengths; that is, a 17mm on a Micro Four Thirds camera, which has a 2X crop factor, is equivalent to a full-frame 35mm (well, 34mm, technically) and is thus listed under “35mm.”


A 35mm is great for capturing wide angles for landscapes, environmental portraits, street photography, documentary photography, and shooting indoors where you can’t simply back up to fit everything in the frame. Here are a handful of budget-friendly options for multiple mounts.

  • Canon EF 35mm f/2 IS USM
  • Nikon AF-S Nikkor 35mm f/1.8G ED
  • Sony E 35mm f/1.8 OSS
  • Fujifilm XF 23mm f/2 R WR (equivalent to a 35mm)
  • Olympus M Zuiko 17mm f/1.8 (equivalent to a 35mm)


A 50mm is a great natural focal length that’s not too wide, but still fits a good amount into the frame. Called a “niffty fifty,” a 50mm f/1.8 is popular in many genres, including portraits.

  • Canon EF 50mm f/1.8 STM
  • Nikon AF-S Nikkor 50mm f/1.8G
  • Sony E 50mm f/1.8 OSS
  • Fujifilm XF 35mm f/2 R WR (equivalent to 50mm)
  • Olympus M.Zuiko 25mm f/1.8 (equivalent to 50mm)
  • Panasonic Lumix G 25mm f/1.7 ASPH (equivalent to 50mm)


The longer the focal length, the more blurred that background will appear — that makes 85mm lenses favored for portraits and other genres where you want maximum background blur. While you can keep going beyond 85mm, this is a well-balanced focal length that isn’t too large (nor too expensive).

  • Canon EF 85mm f/1.8 USM
  • Nikon AF-S Nikkor 85mm f/1.8G
  • Sony FE 85mm f/1.8
  • Olympus M.Zuiko 45mm f/1.8 (equivalent to 90mm)
  • Panasonic Lumix G 42.5mm f/1.7 ASPH Power OIS (equivalent to 85mm)

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