When I first started photography, I didn’t take my buddy’s advice — invest in a better quality lens before upgrading your camera. It was a mistake I never made again. So when it came time to decide if I need a prime lens in my bag, I called on his advice again. Instead of telling me what to do, he explained the difference between a prime and zoom lens plus the benefits of each for me to make my own decision. Here’s how I used his advice many years ago when deciding which portrait lens was best for me.

Understanding prime and zoom lenses

A prime lens — also referred to as a “fixed lens” — is a camera lens with a fixed focal length and a fixed field of view that does not allow you to zoom in or out while taking a photograph. The only way of making your subject appear larger or smaller in the frame is to physically get closer or step back from your subject.

A zoom lens is a camera lens that offers photographers a range of different focal lengths. A simple turn of the zoom ring allows for quick and easy re-framing of a scene while staying in the same physical position.

The difference between a prime and a zoom lens

The obvious difference between a prime and zoom lens was already stated — a prime lens has a fixed focal length and a zoom has a variable focal length. Of the two, a zoom lens offers more flexibility while shooting. So why wouldn’t manufacturers create just one multi-purpose 18-400mm lens? They do, but the quality varies widely. A quality prime lens is very specialized and specific. A prime lens has fewer components so manufacturers invest more money in a higher quality of glass and elements. That’s not to say a 70–200mm f/2.8 lens doesn’t offer excellent quality, it does. But when you compare it to a prime 85mm f/1.4 portrait lens, you will notice a difference.

The key is to determine what’s the main purpose of the lens. If your needs require a wide range of shooting — action sports, events, travel photography, etc. — use a zoom. For specialized shoots — portraits, macro photography and others — invest in a prime lens.

When to use a prime lens

  • Shooting in low-light situations (a prime lens lets in more light)
  • To create a shallow depth of field to create beautiful blurred out backgrounds
  • For sharper photos and better image quality
  • Macro photography

When to use a zoom lens

  • You’re traveling and can’t take a lot of equipment with you
  • You can’t physically get closer to your subject
  • You want to blend in and be relatively unnoticed to capture candid shots
  • To alter perspective, which ‘compresses’ the features of the face and makes the nose appear less significant

My lens choice

I decided to use a combination of a prime lens for portraits — I use the Sigma 85mm f/1.4 for most portraits and the Tamron 35mm F/1.8 for creative portraits — and a Tamron 70-200mm f/2.8 for fast, action sports.

My advice: if you’re on a budget and you have to decide which lens to buy, go with the lens you will use the most and rent the other lens for special projects or assignments. If photography is your business, buy the lens that will increase your profits the fastest. The extra money you make can help you get the additional lens you need.