- What Is a Prime Lens? How is a prime different from a zoom?
- Why Buy a Prime Lens? Convenience isn't everything.
- Types of Prime Lenses With this many choices, are zooms even necessary?
1. What Is a Prime (Fixed Focal Length) Lens?
How is a prime different from a zoom?
It’s pretty simple: Unlike zoom lenses, which cover a variety of focal lengths (like the 18-55mm that probably came with your camera), each prime lens covers just a single focal length.
Zooms are incredibly convenient. They give you access to a variety of perspectives, and you don’t need to swap them out for a different lens when your subject changes. But that convenience has big tradeoffs. Zooms that offer top-flight image quality are huge and heavy, and more portable alternatives (especially those that cover a wider focal length range) often fall short when it comes to image quality.
That’s precisely why many photographers turn to primes, which sacrifice convenience for superior image quality, increased portability, and (in some cases) lower price tags.
2. Why Buy a Prime Lens?
Convenience isn't everything.
There are several excellent reasons to make your next lens a prime lens, particularly if you already own a good all-around zoom.
Portability: Since their designs are less complex, primes are smaller and lighter than zooms. That means you can throw a few primes in your bag and not worry about having a sore neck at the end of a long day of shooting.
Image Quality: Though excellent zooms are available from most manufacturers, the best primes consistently outscore them for sharpness and distortion control. Primes also tend to offer wider apertures, which makes them more suitable for shooting in dim lighting conditions, enables quicker shutter speeds, and helps them produce better bokeh.
Price: The relative simplicity of prime lens designs means they’re often cheaper than zooms, though it’s not exactly an apples-to-apples comparison. Still, as a general rule primes offer better image quality than comparably priced zooms.
Education: Shooting with primes requires you to “zoom with your feet”—to move yourself in relation to your subject, rather than simply turning the zoom ring to bring the subject closer. This teaches you how focal length relates to perspective, and reveals why certain focal lengths work better for certain subjects. In short, shooting with a prime lens requires a more deliberate, thoughtful approach to photography that can help improve your craft.
3. Types of Prime Lenses
With this many choices, are zooms even necessary?
Prime lenses are available in virtually every focal length, covering a huge range of uses. Here’s a quick look at different kinds of primes, and why you may or may not want to consider them.
Wide-angle primes are most useful for shooting architecture and landscapes, though they can also provide a dramatic perspective when used at close range. Just be careful when shooting people, since they can distort facial features. Primes with extremely wide focal lengths or wide apertures can get very expensive, since they’re more difficult to design than other primes.
Normal (aka “standard”) primes offer a field of view similar to the human eye. That makes them great general-purpose lenses; they’ve found work in photojournalism, street photography, landscapes photography, and people shots. They’re usually fairly compact and affordable—many manufacturers make one in the $100–$300 range—though the finest examples can get quite expensive.
A good portrait prime has two key traits: a longer-than-“normal” focal length and a very wide aperture. The long focal length allows them to isolate your subject’s face, and the wide aperture creates a beautifully blurred background. Some macro lenses work well as portrait lenses, though they can actually be too sharp.
Telephoto primes use very long focal lengths to bring faraway subjects up close. That makes them perfect for shooting sports and wildlife, and a particular favorite of birders. Telephotos are some of the largest and most expensive prime lenses on the market, though notably smaller than comparable telephoto zooms.
Macro lenses are a breed apart, designed to render extremely fine details at life size, or something close to it. They’re ideal for getting shots of small subjects, like insects or watches, though they can also be used for portrait work. True macro lenses offer reproduction ratios of 1:2 (half life size) or greater; don’t be fooled by other primes and zooms that call themselves macros but offer lesser reproduction ratios. While they come in a variety of focal lengths, the vast majority fall into the 90 to 105mm range.
Most of the photography world's special purpose lenses are also primes. A good example is fisheye lenses, which embrace distortion rather than trying to fight it, giving you a unique perspective on the world. Tilt-shift lenses combat a specific kind of distortion—keystoning—to provide perfectly straight lines in architectural shots. Selective focus and toy lenses (like the popular Lensbaby and Lomography primes) help create Instagram-style looks in DSLR shots.