One of the most common questions asked by those starting out in photography is “which camera do I buy?” As much as some people will try to convince you that there are right and wrong choices when selecting a camera, there aren’t. There is no magic formula, no precise science, just your own personal experiences. Here, I will attempt to give a little background into the various features and specification of a modern day digital SLR to help you make an informed decision.

Features – The biggest difference between a “professional” and “consumer” camera are the features that come with each. It is important to determine which features are important to you and go from there. Pro cameras, such as the 1D series from Canon and the D3 series from Nikon, usually have more robust and faster shutters, better battery life, an integrated vertical grip, weather resistance, better autofocus and exposure systems, and more robust data pipelines. All of this comes at a price tho – namely size and cost.

Battery – Better battery life means longer periods between recharges, but also means a larger and more expensive battery. Batteries these days are good enough to last you several days without a recharge, even at the consumer level, so there is no real need to go to a larger one unless you go for long trips away from electricity. Made for the most part of lithium-ion, they have no memory – meaning you can charge and discharge them at any point, without concern for the overall health of the battery. Contrast this to batteries of yesteryear, which would easily become damaged if not recharged at exactly the right time. A battery to a Nikon D3 is approximately 3 times the size and weight as a battery from a D90, yet takes the same amount of time to charge, and lasts over 10 times longer. Stay away from any cameras that require disposable batteries – it will eat them up and quickly consume any money you saved on a system that uses rechargeable batteries. The only purpose consumable batteries serve is as a backup, which even then is debatable.

Weather Resistance – Key word here is “resistance.” This does not imply that you can drop the camera into the ocean and expect it to keep working – it means more a resistance to light rain and snow. Consumer cameras, for the most part, are not sealed in any way. HIgher model cameras place o-rings and gaskets around all buttons and possible entry points of water, minimizing the chance of entrance. While this minimizes the chance of leakage, it does not eliminate it. Great care should be take, even with the best cameras, to use protection while shooting in adverse conditions. That said, it is rare to hear of a sealed camera failing due to shooting in rain.

Shutter – There are two measurements pertaining to the shutter – life expectancy and speed. Most consumer shutters are rated at around 100,000 exposures, while pro models are more around 300,000. Unless you’re going out and shooting hundreds of images each and every day (like a professional would), chances are the camera will become obsolete before you even come close to hitting either of those ratings. Shutter speed, rated in Frames Per Second (FPS), ranging from around 3FPS on most consumer models, to 9+FPS on top end pro models, is perhaps a more important feature. For sports and action photography, a higher frame rate is necessary to insure that “once in a lifetime” picture is captured. If you aren’t shooting any action however, having a camera with a high FPS is like owning a race car in the middle of the city – doesn’t do you much good. Higher life expectancies and shutter speeds only add to the weight and price of the camera.

Megapixels – Despite what you may think, more is not always better. A megapixel is a million pixels – dots that make up an image. The more you have, usually the greater the detail of the picture, allowing you to enlarge it to a greater degree. While it’s great to have a lot of detail so that you can print nice and large and zoom in to see the reflection in someone’s eye, how often do you print billboards?

More pixels usually means a few problems. Firstly, it means having to buy larger and more expensive memory cards and hard disks to hold the files. While you can change the size of JPG files the camera generates, you cannot change the size of a RAW file (the most flexible and powerful file format). A JPG from a higher resolution camera is usually worse then a RAW from a lower resolution camera. More megapixels also means that you’ll reach the limits of your lens quicker, forcing you to buy better glass and be more careful with how you use it. Lenses encounter something called diffraction – scattering of light. Just like if you take a magnifying glass to an object, you’ll notice all the defects that were otherwise invisible at a normal distance, having too many pixels can cause the camera to pick up light that would otherwise be missed, negatively affecting quality.

The average dSLR is around 6+MP. A file of this size will allow you to print an 8×10, and should easily enlarge to give you a print double that size. I have personally made 17×22 prints from a 4MP camera, proof that it is possible. It is important to gauge the cost of owning a higher resolution camera against the benefits it poses to you.

Lens – Almost more important then the body is the lens. It is a universal property of bodies that they will all take pictures. How fast and how many pixels and the features are all variable, but they will all take pictures. The lens on the other hand, specifically defines how you will use the camera. You can’t use a wide angle to shoot sports, and you can’t use a zoom to shoot events. PIck a lens that suits what you do most. I recommend starting out with two basic lenses: a 50mm f/1.8 prime lens and a zoom lens.

The 50/1.8 ca be found from just about any manufacture for around $100, and is usually one of the best lenses produced. It allows photography in extremely low light conditions, is as compact as they come, and is something you’ll wind up owning later on down the road anyways. A zoom, covering as wide a range as possible (around 20-200) is the other useful lens to have. While it is usually true that the more focal lengths a lens covers, the worse it covers all those focal lengths, a zoom covering a wide range will allow you to dial in on what you feel most comfortable doing, and allow you something to play with until you’re ready to take the next step. If you’re already at that next step level, consider trading in that ultra zoom and going for a fixed aperture zoom (aka always stays at f/2.8). Fixed aperture zooms are usually a sign of a higher quality lenses, as it take quite a bit more engineering and time to manufacture, and as such, special attention is paid to detail.

You may also want to consider purchasing a specialized lens if you know you’ll be doing a specific kind of photography. Macro lenses allow you to get especially close (sometimes within centimeters) to a subject, reproducing it in a 1:1 ratio. A 1:1 ratio means that the size of the object in real life will be equal to the size of the image that hits the sensor. This is generally viewed as the optimal ratio for detail. Tilt / shift lenses, defocus control lenses, and other specialized products all have their place for more specific applications, such as architecture and portraits.

Brand – There is an entire ocean full of arguments over the subject of brands. The two biggest and most debated brands are Nikon and Canon. Each has its own minor ups and downs, but both are, for the most part, equal. In the end, what it comes down to, is what you are most comfortable using. Nikon is known for having superior glass and ergonomics / user interfaces, while Canon is known more for their high resolution bodies and sport geared lenses.

I suggest going to a local camera shop and spending a few minutes, hands on, with some of the various cameras. See which feels more natural, which you feel you could learn quicker, and be more comfortable using. If both brands seem like they would work just as well for you, go for the one that you have products from already. Things like lenses, flashes, programs, etc, can be easily used between cameras of the same manufacture, but usually not across different brands. If you don’t own anything yet, take a look not just at the body itself, but the range of lenses, flashes, and accessories. Chances are you’ll wind up owning more then just a body and a lens, in which case it’s important to pick a camera by the system, not just the camera itself. In the end, if all else fails, flip a coin.