THE QUESTION ASPIRING PHOTOGRAPHERS ASK more often than any other is this: “Which is the best camera on the market.”

In a way, this is the wrong question. What they really want to know is which is the best camera for THEM.

There are many excellent digital SLRs on the shelves of any camera store, each with its own set of advantages and disadvantages, each with its own shortcomings and capabilities, and a camera which is perfect for one photographer may be of virtually no use to another.

Think of Canon’s 1Ds Mark III for a minute. It is a spectacular camera, with an astonishing 21 megapixels, and it is virtually unbeatable in the studio, but it can take a maximum of 5 pictures per second, which may be too slow for sports and wildlife photographers. It is also very heavy and a pain to lug around on long hikes.

Nikon’s D300, on the other hand, can shoot at 8 frames per second, it is much lighter and the smaller sensor size, which magnifies the length of lenses, makes it a good choice for sports snappers, but the lower pixel count makes it inferior to the 1Ds in the studio.

Unfortunately the range of features available from modern digital SLRs can be quite overwhelming for the newcomer. From MGP to FPS and Megapixels to shutter lag, the shear amount of abbreviations and jargon is a maze of minefields for the unwary.

If you are considering buying a camera, and are unsure about where to start, have a look at our breakdown of what it all means and choose the body that’s right for you.

A system, not a camera

Buying the right camera body is the most important choice a photographer makes when selecting his gear. Not only is it generally the most expensive item in the gadget bag, it is also the centerpiece of his kit.

What you need to remember, is that you are buying into a system, not just a stand alone body. Once you have chosen a body from a specific manufacturer, you will start buying lenses for it, and perhaps even a flashgun. These are, for the most part, not interchangeable between manufacturers. A Nikon lens will not fit a Canon camera and a Minolta flashgun will not fit an Olympus body.

Of course, there are independent lens makers, such as Tamron and Sigma, but even for them, a specific lens is made to fit a specific body, for instance, when you order a Sigma 70-200mm f2.8 lens, you will be asked whether you want, amongst others, a Canon, Nikon, Pentax or Olympus mount. These are not interchangeable, and cannot be adjusted afterwards. One lens is made to fit one manufacturer, end of story.

What this means is that you have to tread very carefully when selecting your first camera, because it may cost you thousands to change manufacturers later on. Make sure that there is a wide range of lenses and accessories available and that you will have adequate support from the servicing and repair centers, should things go wrong.

Pixel Count

The headline feature for digital cameras, the one first quoted by manufacturers and salespersons alike, is the number of megapixels. And make no mistake, the pixel count is important.

Have you ever looked closely at a newspaper photograph? Noticed how it’s made up of little dots? Well, a digital photograph works on the same principle. It is made up of little digital dots. And the number of megapixels is the number of little dots, in millions, i.e. a 6.1 megapixel camera’s photographs are made up of (roughly) 6 100 000 dots or pixels. The more pixels, the sharper the picture, and the more you can enlarge it before it starts to break up and pixelate.

But because this is the headline feature, because it is the specification which is most quoted, manufacturers have put a tremendous amount of research and development into stacking as many pixels as possible into the digital sensors, and we’ve now reached the point where the number of pixels available on the average DSLR far outstrip the need of the average photographers.

Indeed, some rather inexpensive models, such as the Pentax K20D feature sensors with 14.6 megapixel sensors. But the difference between this and, say, 10 megapixels will be indiscernible at normal printing sizes, and even enlarged up to 8x10 inch size, you would probably need a magnifying glass to tell the difference. The lesson is that if you aren’t going to blow your pictures up to anything approaching billboard size, then any sensor over about 8 megapixels will be more than enough.

Sensor Size

Quite apart from the pixel count, the actual dimensions of the sensor is very important. Not all sensors are the same shape and size, and the pixel count is no indication of the actual, real-world dimensions. One 12 megapixel sensor may larger than another, and this has some profound consequences for the images captured by a given camera.

To understand how this works we need to first look at the mechanics of a lens.

A lens casts a circular image, which should be large enough to cover the whole of the digital sensor. But say we are using one lens, which casts a circular image of a given size. We now put a large sensor, of say 12 megapixels, in this circular pool. Now put a second, smaller 12 megapixel sensor in the same pool of light. The resulting images will appear different. Most notably, the second image will appear more magnified than the first image. In effect, it will look as if you used a longer lens for the second image than for the first, even though the two pictures resulted from the very same lens. This effect can be quite pronounced, so much so that a 2:3 ratio of magnification is common with many digital cameras as compared to their 35mm film counterparts, meaning that a 200mm lens will have the equivalent magnification factor on some digital SLRs as a 300mm lens would have had on 35mm film.

Smaller sensors, then, magnify the power of your lens, and telephoto zooms become even longer than they were before. This is a tremendous advantage for sports and wildlife photographers, who generally want as much zooming power as they can get. But at the other end of the scale, if you need very wide lenses, as is common in landscape photography, you will see this as a disadvantage, because your lens which previously had the angle of view of an 18mm lens will now be restricted to the same field as a 24mm.

Smaller sensors will also deliver more depth of field for a given aperture setting. Again, this can be an advantage or disadvantage depending on the type of photography you like to do, and whether you would like to keep the whole of the picture in sharp focus, or a very small part of the image sharp with all the rest blurred.

Size and weight

Of course, it’s not only the size and shape of the sensor that matters, you will also have to have a close look at the physical dimensions of the camera itself. Is it big or small, heavy or light. If you need to carry it for miles while out hiking, you will want a body that won’t weigh you down. If, on the other hand, you are a studio or house bound beast, the weight won’t be such a factor. But also be sure, if you are a bloke with monstrous hands, the camera is not too small and fidgety, or you may be uncomfortable using it in the future.

Buffer size and frame rate

These two, closely related specifications will mainly be of concern to people who take pictures of fast moving subjects, like action or press photographers. The frame rate determines how many pictures you can take in a given amount of time, and is measured in frames per second (fps). This rate can be quite slow for many cameras, as low as 2 fps, so be aware of this if you like to snap away in a blaze of glory. Many cameras have two settings, a slower frame rate at full resolution, and a faster rate in ‘cropped down’ mode, meaning that the camera uses a smaller pixel count. This is a worthy compromise, allowing you the choice between speed and quality, but be wary if the drop in image size is too great. We have noted one manufacturer with a 14.6 megapixel sensor, which crops the image down to 1.6 megapixels for the higher frame burst rate, leaving images that will be to small for anything larger than a 3x5inch print.

The buffer size refers to the number of consecutive images that you will be able to capture consecutively at the full frame rate. So, for instance, if a camera has a frame rate of 8fps and a buffer of 50, that means if you hold the shutter release button down, it will take 8 frames per second for 50 consecutive frames before it runs out of memory. The buffer size is very important if you expect to take a lot of images in succession, because once it is full, it can take more or less a lifetime to download to the card and clear the buffer so that you can start taking pictures again.

ISO range and sensor noise

Most cameras will perform fine and dandy in bright sunlight. Take them out after dark and the story changes completely. The ISO of any given camera can be adjusted along a scale starting at about 200 ISO to about 1600 ISO. Each time the number is doubled you will need half the amount of light you needed before. So if one camera only goes up to 800 ISO while another goes up to 1600 ISO, that means you will need twice the amount of light to take pictures with the first one.

Be careful, though, because as you increase the sensitivity of the sensor, the amount of noise (which looks a bit like film grain, or the dots of a newspaper photograph) generated by the camera also increases, and noise is not constant across various cameras. One camera may have much more noise at 1600 ISO than another. Ideally, if you like shooting in low light, you will need to download some sample images taken by the camera at high ISO.

The LCD

Back in the days of 35mm film photography, we all had to wait until the reel was developed before we could see our images. So much for the bad old days…

Today you can review your images instantly, and far from just a way of showing off pictures to models and an awestruck audience, the LCD has become an integral part of the way we take pictures. Photographers use it to see whether the image is correctly exposed, whether the focus was sharp and whether the composition was adequate. Indeed, it has become the first port of call for on the spot troubleshooting and is an integral part of the workflow.

Provided, that is, the screen is up to the task. A small screen is worse than none at all and can hamper your progress, decent sizes are around 3 inches across on cutting edge models, but if you are opting for a smaller camera, the screen will naturally be smaller as well.

Number of focusing points and meter segments

With both of these, higher is better, but in all honesty these are less than crucial in selecting the ideal camera.

Memory Card slots

The type is not crucial, as they all pretty much do the same job. Compact Flash seems to be in the lead at the moment, as it is more durable, offers impressive amounts of storage and is easily manageable due to their physical size.

What you do want to check, however, is that the slot is easy to get to, easy to open and that you can quickly swap cards if you have filled one up. Some cameras have more than one slot, which is a very handy feature if it churns out massive file sizes that fill up 8GB cards in a jiffy.

Battery life

This is crucial, especially if you plan to take the camera travelling in remote areas, but unfortunately not really reliably indicated in the manufacturer’s specifications. For true indications and advice on how a particular model performs, read up on internet forums.

Built-in Flash

There is one feature that is common in lower-end cameras, yet completely absent from the top of the range models, and this is a built-in popup flash. The reason for this is that the average popup has a very low power output, and that it often takes a very long time to recharge. It is assumed that if you are using a camera at the expensive end of the spectrum, you will also splash out on a decent flashgun.

Other features

Digital cameras are very much a developing product, and new innovations are shaping the market all the time. Not too long ago Live View, where you can look through the lens using the LCD, rather than the view finder, was completely absent from all DSLR, and only available on compact cameras. Now that has changed, and virtually all new models have the feature as standard. And soon, no doubt, cameras will be able to make tea, but whether you allow the latest wiz-bang feature to sway you in your choice should depend entirely on whether or not it will help you take better pictures, because that, after all, is what cameras are for.