Whether you have an entry-level digital SLR camera or a more advanced model, there's one constant truth: you can always buy a better lens.
Different lenses from your camera manufacturer or from a third-party brand can help your shooting -- whether you want to take different kinds of photos, or want to improve on the photos you're already capturing.
There's a wide variety of different lenses, though, so there are a few key points to consider before purchase.
Zoom Lenses Vs. Primes: What Do You Need?
A very quick distinction, that significantly cuts down your choices, can be made in your lens buying decision. All you need to do is to decide whether you want a lens with a variable focal length, or a fixed one. Do you want a lens that can zoom in and out, or is that unnecessary?
It's not as silly a question as it sounds. Prime lenses -- the kind that don't zoom -- are generally able to deliver sharper, more contrasty photos than their zoom counterparts, and are smaller, simpler, and cheaper to boot.
Zoom lenses are more versatile -- you can stand in one spot and take photos that look entirely different -- but they're larger, heavier, and can, in the case of professional-grade zooms, be prohibitively expensive.
If it were up to us, we'd stock our camera bag with a few high-quality prime lenses, rather than zoom lenses, and zoom with our feet. Simply walking around to get a different angle on your composition can help your photography more than you'd think.
Special Purposes: What Do You Want To Photograph?
If you find your camera's 'kit' lens -- the lens that was included in the box -- isn't cutting the mustard, try to work out what you're not happy about. Is it not focusing fast enough, or is it struggling to focus on close-up subjects? Do you need a wider zoom range, or can you choose a lens that's designed purely for ultra-wide landscape photos or telephoto paparazzi-style bird-watching?
Beyond the basic prime lens versus zoom lens distinction, there are a few special-purpose designators that DSLR lenses can carry. We'll run through a few of them here; if something catches your fancy or sounds like it's something you'd like, consider it when you're about to buy.
Macro lenses are designed to focus ridiculously close to their front element, and can often clearly define an object within a couple of centimetres' distance. If you want to snap flowers or insects, a macro lens is for you. Macro lenses also generally have a flat plane of focus, so the corners of your photo won't be any less sharp than the centre -- and can show amazingly high levels of detail across the frame.
Constant aperture zoom lenses are able to let in the same amount of light when fully zoomed in as when they're fully zoomed out -- a deceptively minor-sounding issue that cheaper lenses generally don't offer. Having a constant aperture lens saves you complicated guesswork - "oops, I've zoomed in, now I have to halve my shutter speed or bump up the ISO" - while you're shooting.
Tilt/shift lenses are special-purpose designs that let you manually adjust the orientation of glass elements within the lens, compensating for (or exaggerating) both vertical tilt and lateral shift.
Although they're ostensibly meant to be used for architecture work, where applying a tilt can flatten the lens's plane of focus and straighten distorted lines when pointing upwards at a building, they're equally fun to use in the opposite fashion -- heavily distorting and compressing a lens's plane of focus, letting you capture otherworldly, heavily blurred out-of-focus areas in your photos. They're pricy, though.
Image stabilisation, equally well known as vibration reduction or optical stabilisation, works a series of gyroscopic motors in a lens to compensate for any accidental camera shake. When you're hand-holding a heavy lens, your arm's natural shakiness, or even the fatigue of holding one position for an extended period of time, can lead to fuzzy photos or Cloverfield-grade shaky cam footage.
Stabilised lenses (generally only zooms) are more expensive, but they give you peace of mind -- no more shots wasted and deleted thanks to an accidental bump or movement during your photography.
There are dozens of different form factors to choose from when you're picking out a new lens - including some we haven't mentioned here, like waterproofing, manual focusing, and overall focal length. But armed with a better idea of what different camera lenses can do, we're confident you'll be able to choose a new lens that will make your photography experiences more enjoyable.
Do you have a favourite lens?