If you own just one digital SLR and lens, it is more than likely that the lens you have is the kit lens sold with the camera body when you bought it. The kit lens is good enough to get you going, and versatile enough to be useful in a number of situations, but it's not a great lens.
It has limitations, and as your photography improves you will bump up against them. In this article, I'm going to explore some of those limits and take a brief look at the alternative lenses you could consider buying to upgrade your kit.
A Canon Kit Lens
Let's start by looking at a typical kit lens, the EF-S 18-55mm f/3.5-5.6 IS II currently sold with the Canon EOS 550D, 600D and 60D bodies.
A close look at this lens reveals that it is built of plastic, and fairly small and light. It doesn't have great autofocus performance and doesn't come with a lens hood. It's not weatherproofed and the build quality means that it won't survive many knocks.
This lens will get you going, but don't expect great things from it. In the UK, the difference between buying an EOS 600D body only and a 600D with this kit lens is only around £80. That tells you how much the lens is worth.
Kit lenses are inexpensive because the major camera manufacturers want to keep the prices of their camera kits down to encourage people to buy them. They don't want to skimp on the camera body itself, as they know they have to make great cameras to keep up with the competition and encourage users to upgrade from older models. So the savings are made with the kit lens.
However, if you own a kit lens, don't let that stop you taking some wonderful, creative images. There are a couple of features that make the Canon lens particularly useful (and your kit lens, if you have a different one, may share them):
Four stop image stabilisation (IS) helps you take photos that aren't blurred by camera shake in low light, or when using a combination of a small aperture and low ISO.
For example, if you were using the 55mm end of the lens, I would personally recommend a shutter speed of 1/100 second to eliminate camera shake. With IS activated, you could theoretically drop down to around 1/6 second and still get sharp images.
A minimum focusing distance of 25 centimeters. This lets you focus quite closely in on your subject. You may be surprised at how close you can get, especially at the 55mm end and used with a crop sensor camera. While it's not as close as a macro lens will get you, it's ideal for close-ups of subjects like flowers.
Using Kit Lenses
The kit lens is an often maligned piece of equipment. Yet the latest kit lenses are not bad pieces of equipment. The image quality is decent, and while the build quality and autofocus performance doesn't match that of more expensive lenses, they perform their task quite well; which is as a general purpose lens to get you started with your camera.
My first digital SLR was an EOS 350D with a kit lens. I wasn't sure which lenses to buy for it, so I decided to stick with the kit lens and make up my mind about other lenses later, and took it on a trip to South America with me.
I soon found out the kit lens wasn't up to much – it was prone to ghosting and flare and there was a lot of barrel distortion at the 18mm end (it has since been discontinued and replaced with the kit lens shown above).
But, I still got some good photos with that lens. The photos that illustrated my first published article in a photography magazine were taken with it.
I've also used photos taken with it to illustrate other articles and ebooks. It's not a great lens, and I would have been better served by taking a better one, but it was all I had and it didn't stop me. Here's the article:
The lesson is that, regardless of what you think of the lens or lenses you already own, they are probably better than you think, and you shouldn't let your perception of their performance affect the creative side of your photography.
If you're in a position where you can't afford to upgrade to a better lens just yet then just relax and work with what you have. Learn to get the best out of it, and what its limitations are, and this information will help inform you when the time comes to buy a better piece of glass.
Where Equipment Comes From
As an aside, you may be wondering where professional photographers get the money from to buy the expensive cameras and lenses they use to create their images.
'Gear envy' occurs when you look at the cameras and lenses the pros use and start to believe that you need the gear they own to create the sort of images they produce. To an extent that's true. A super sharp, expensive lens in the right hands will always give an image with better technical quality than an inexpensive kit lens.
However, more professional photographers than you might think started off with basic equipment, learned to make the best use of what they owned, and then purchased better quality cameras and lenses when they were able to do so.
Professional photographer Jingna Zhang has a written a great article on this topic. You can read it here.
Limitations of Kit Lenses
Having said that, it is reasonable to acknowledge that kit lenses aren't perfect and that there are valid reasons for upgrading to a better lens. A quality lens should last you many decades, much longer than most digital camera bodies. Money spent on good lenses is a long-term investment in your photography. Here are some of the reasons that you might do that:
Better image quality
This is an excellent reason. There's no doubt that you'll get better image quality by buying a prime lens or a more expensive zoom. The better quality the lens, the less barrel distortion, chromatic aberrations and vignetting at wide apertures it should have.
It's a good idea to avoid 'superzoom' lenses though. The following comparisons show you why. The first was taken with the same 18-55mm kit lens the magazine article was shot with (at 18mm). There is strong barrel distortion. The edge of the platform should be straight, but thanks to the barrel distortion of the lens they are bent. I've added red guidelines so you can see just how bent they are.
The next image was taken with an EF-S 18-135mm zoom at 18mm. The focal length range of this lens is just too big to get good image quality at every focal length. Something has to give somewhere, and you can see that the barrel distortion is even worse on this lens. No guide lines required – that bent line at the bottom is meant to be straight.
The third image was taken with an EF 17-40mm f/4 L lens at 17mm. I'm going to ask you to ignore the bikini clad model for a moment and look at the lines. There is some barrel distortion, but not nearly as much as in the previous image. That's the difference a good quality lens makes.
Wider maximum apertures
The aperture range of a kit lens is limited, especially at the telephoto end. For example, the long end of most kit lenses has a maximum aperture of f/5.6. Compare this to a 50mm lens with its maximum aperture of f/1.8. That's a three stop difference.
Those extra three stops really help out when shooting in low light, or when you want to limit the depth-of-field for creative effect. The image above was taken with an 85mm prime lens and the aperture set to f2.8.
Primes have wider apertures than zoom lenses, but there are still zooms that keep a maximum aperture of f2.8 or f4 throughout the focal range.
Why is the aperture range of a kit lens so limited? Part of the reason is that lenses with wide apertures required larger lens elements. A narrower maximum aperture helps keep the size of the lens elements smaller, and the manufacturing cost of the lens down.
Better Build Quality
This could be important. There is a huge difference between a plastic kit lens and the manufacturer's top end lenses. Canon's L series lenses, for example, are weatherproofed and designed to work with Canon's professional One series cameras, which are also weatherproofed. If you intend to shoot in poor weather conditions (and many pros do), this matters.
To Explore Different Focal Lengths
You might wish to explore the use of focal lengths outside of the 18-55mm range (or the range of your particular kit lens). The focal length of the lens has a huge effect on the aesthetics of the photo, and you can get some creative effects by using a wide-angle lens or a telephoto.
If you would like to try out nature or sports photography, then you will almost definitely need a telephoto lens of some sort. The photo of the tango dancers above was captured with the 150mm end of a Sigma 50-150mm lens.
To Get Closer
If you like close-up and macro photography then you may consider buying a macro lens. These let you get closer to your subject for greater magnification and are designed to give their best optical performance at close focusing distances. I took the previous photo with a Canon EF 60mm macro lens.
To Use on a Full-Frame Camera
Kit lenses are normally designed to work on a crop sensor camera, and won't work with a full-frame camera body. If you intend (or hope) to upgrade to full-frame one day, then you need to buy lenses that work well with full-frame camera bodies.
Good lenses are an essential component of any photographer's kit. If you have a kit lens, at some point you may want to upgrade. This article is a good starting point. Once you have identified what subject you want to shoot and your budget, you can start looking at the options and making decisions.
And don't forget, there are many more useful articles about lenses at the Phototuts+ Lenses Session.