If, like me, you graduated to digital SLR photography from digital point and shoots, you’re very familiar with zoom lenses: they’re flexible, easy to understand and mean you get tightly-framed shots (or expansively wide landscapes) without swapping lenses or having to walk back and forth to compose your shot.
This sounds good, but for SLRs this flexibility comes at a very high cost in image quality, low-light ability, creative control, price and stealth capabilities.
The truth is, unless you’re completely loaded, most of the time you’d be better off shooting with lenses that don’t zoom – prime lenses.
Let’s look at the benefits:
Image Quality
Manufacturers have a problem with zooms: flexible, high-quality, inexpensive – pick any two.
Most consumer zooms are inexpensive and flexible – allowing you zoom across a wide range of focal lengths without costing too much (this is especially true of the kit lenses that come as a package with your camera).
So it’s image quality that suffers – things tend to be soft (especially at lower apertures), with noticeable distortion at both ends of the zoom. Contrast and color rendition aren’t great either.
There are some notable exceptions – for example, the Tamron 28-75mm f/2.8
Fast is good
Many consumer lenses have lowest apertures of f/3.5 or f/4.5 (and often the longer the focal length, the higher the aperture. This means that in subdued light, you’ll need a slower shutter speed than if you were using a lens with a lower aperture, say f/1.8.
Which is why zoom lenses tend to depend on a flash – you won’t be able to hand-hold reliably at shutter speeds slower than around 1/50th of a second, and even if you could (you might have image stabilization, for example), any movement in the subject will result in blurriness anyway.
You can use the flash of course, but the flashes built into most SLRs will leave your shots flat and lacking in shadows and warmth.
A minimum aperture of f/4.5 can also result in a wide depth of field – the higher the aperture, the wider the depth of field. This limits your flexibility in blurring the background – meaning you often can’t get the nice ‘bokeh’ or blurry background that makes your subjects pop (like this butterfly).
So even if you’ve enough light, your creativity is limited by the slower lens. There are just a lot of shots you won’t be able to get with the slower zooms.
The ultimate stealth lenses
Prime lenses tend to be small and light – making them perfect for a bit of unobtrusive street photography, or just if you don’t want to scare your friends at parties.
My Canon 50mm f/1.8 II lens. is a ridiculously light 8 ounces, and the 28mm f/1.8 USM
If you’re going somewhere and want to bring a camera just in case, throwing on a prime makes the whole package a lot more discreet. This works particularly well at indoor parties, where the low-light capabilities of the primes can also be a life-saver.
Become a great composer
In the old days, nobody had zooms. Henri Cartier Bresson, who took some of the best photographs the world’s ever seen, predominantly used a Leica ragefinder with a 50mm lens.
I’m not saying that using a prime is suddenly going to make you a fantastic photographer, but one thing it will definitely make you do is think more about your shots, which could be the first step towards making some improvements.
Because you can only zoom with your feet, you have to consider your composition more carefully. You start looking at everything in the frame, and deciding what really matters, rather than just zooming into the obvious subject.
It’s a bit like racing cylists’ early season training. The old rule was not even to use the large chainring (for faster speeds) until you had hundreds of miles in your legs. Using a prime lens can improve your technique, so you have a good base when you use the zooms.
Give it a go
So there you have it – primes are fast, cheap, take high quality images, and can improve your photography. What else do you need to know?