You may have heard the term “kit lens” before and wondered what, exactly, a kit lens is. Technically, any lens that is bundled with a camera is called a kit lens. However, it is common to hear people say “kit lens” when they actually mean the 18-55mm lens that comes bundled with a camera.
The most common kit lens is the 18-55mm lens, and for a good reason: it is cheaply made, and therefore cheap for you to purchase. Sure – it's better than nothing, and when you're just starting out this is a great way to get into DSLR photography. Bear in mind, however, that you will not typically get fantastic photos with this lens.
If you're purchasing your first DSLR, you can pretty much expect that it will come bundled with the 18-55mm kit lens. However, some pro cameras come bundled with a good lens, and (by our definition above) those higher quality lenses are still referred to as “kit lenses”.
Let's talk for a minute about why kit lenses are generally looked at as the “starter” lens. One obvious reason is that they come with your camera. But there are some other important things to know about kit lenses:
- Kit lenses usually aren't sharp. You can certainly take pictures with them, but you're not going to get a very crisp, clean shot in terms of sharpness. (Read here for more suggestions if you're having trouble getting sharp photos.)
Kit lenses generally have variable apertures. Perhaps you've seen this before: You are taking a picture, and you've got your lens zoomed all the way out with your aperture set to f/3.5. Then you decide you'd like to zoom in a bit. Suddenly the aperture has changed – now it's 5.6. What happened? This phenomenon is called “variable aperture”. You can read here for a longer explanation, but the gist of variable aperture is that the widest your aperture can open depends on how far your lens is zoomed in. At farther distances, the lens is able to use a wider aperture while at closer distances that aperture closes down. This can be pretty confusing for a new photographer, so it's something to be sure and understand about your kit lens from the beginning.
- Kit lenses are typically cheaply made with plastic, instead of metal like the high quality lenses. Is this a deal breaker? Well, no; you'll still be able to take pictures with your kit lens, and you'll likely get a lot of use out of it before it falls apart. But is your kit lens going to withstand much abuse? Probably not. It wasn't designed with durability in mind – it was designed to function adequately while being as inexpensive as possible.
Do these things mean your kit lens is bad? Should you immediately throw it out and go spend some big bucks on a more expensive lens? When you're just starting out, the kit lens is going to work just fine. Use it while you're learning. Learn to take good photos. Learn how to use your DSLR camera, learn how to control your lens, and learn how to take the best photos you can with the gear you have. But at some point, you will outgrow your kit lens.
Many photographers, when they outgrow their kit lens, purchase the 50mm prime lens as their next lens. It is still relatively inexpensive, but it will be quite an improvement over the kit lens in terms of sharpness. Since there is only one focal length that a prime lens needs to perform well at, it takes a lot less energy and expense to produce. You can find a 50mm prime for around $100-$200, depending on the brand. Check out our Recommended Gear page for links to some good lenses.