Tips for Buying a Digital Camera

Digital vs Film Cameras

Why have so many photographers - professional and amateur - switched from film cameras to digital? Originally there was resistance from the professionals because the quality that digital photography offered was significantly less than film quality. But now, the quality of digital images has all but caught up to what is possible with film, and certainly any images I print (up to 13"x19") are handled by digital just as well as film. (Quality printers and paper for the non-professional market have improved, too.)

The real reason why I switched is because digital cameras allow you the ability to see the results of your shoot immediately, without you having to go home and develop the film before you figure out what you should have done differently. It also gives you the freedom to delete bad images immediately, without having to pay for any extra materials - I can't tell you how many rolls of film I've wasted with poor shots, only to throw them away and be frustrated. With digital, I don't care how many shots of the same thing I take unless I'm close to filling up my flash card. If the sun comes out after you've taken your last shot, you can delete it and snap another.

ISO is also conveniently handled with digital by giving you the ability to change the ISO setting in between shots. In the film cameras, you had to wait until you were finished with your current roll of film before rewinding and switching your 800 ISO-rated film to a 100 ISO-rated film. What a pain!

Camera Features

SLR   vs   Point & Shoot
Number of Megapixels
zoom magnification
Light Metering
I frequently take"action" photos
maximum aperture
shutter speed
flip-out viewfinder
storage card type

For a full list of features, see Part One of my eBook series: Choosing your Camera and Accessories

SLR = Single Lens Reflex
Translation: interchangeable lenses

SLRs are for the more advanced amateur photographer, and are typically more expensive than P&S. The advantage of changing lenses comes into play when photography is a serious hobby.

Printing standard 4"x6" images: 3 mp should be more than fine

Displaying images on the internet for friends and family to see: 2 mp should be more than fine

Printing 8"x10" images: the experts say that 6mp is required for this, but I say it depends on your printing process, and the software you use to enlarge your images. I've printed gorgeous 8"x10" images with a 3.34 mp camera, but I have an expensive/professional printer, and used PhotoShop to increase my image size

Ignore all digital zoom specs when considering which digital camera to buy - and seriously consider never using it! It is much better to rely on well-proven algorithms in software processing once you've transferred your images to your computer than on the in-camera digital zoom. If you've been regularly using digital zoom and wondered why your pictures did not look that great, now you know.

The only time you care about digital zoom is if you don't have access to software to edit your photos, but most cameras come with such software these days, so that's highly unlikely.

Your eye can detect far more "stops" of light than a digital camera can, which means that images with a wide range of darks and lights is difficult to capture correctly. To properly expose a picture, your camera has to measure how much light is available. There are 3 common ways for a camera to do this:

Centre Weighted-Average light measure gives extra weight to the centre of the frame, then averages it with the rest of the frame.

Spot Metering tells your camera to take its light measurement only on your main subject.

Matrix Metering takes light measurement from various areas of the framed shot and then sets the exposure accordingly.

Having various metering methods available to your camera will ultimately end up in better-exposed photos, especially if your camera has good logic to automatically select a metering method for you. Each type of metering has its strengths and weaknesses.

For example, if you're using spot metering to take a photo of a dark horse on a sunny day, the meter might be "fooled" by the bright light all around your main subject, and the main subject might come out underexposed. Similarly, if your subject is off-center from a lake reflecting a sunset, the meter might be fooled into correctly exposing the sunset, while underexposing your subject.

Different cameras have different light metering schemes, but they are mostly variants of the three basic ones in the column to the left. You would want to favor digital cameras that give you all three light metering options.

To successfully capture action shots, you should consider buying a camera with the following criteria:
1) a fast shutter speed (say, of 1/1000th sec. and faster)
2) a large aperture (say, of F1.8 and larger)
3) a powerful flash
4) ISO of 400 and above
5) white balance for fluorescent and tungsten lighting
6) a small shutter lag (you'll never catch the action if the shutter clicks 2 sec. after you press the shutter release)

The maximum aperture decides how much light your camera lets in to record the picture. The larger it is, the more light gets in, thus allowing you to shoot in a bigger range of lighting situations.

Some digital cameras have a limited aperture range. Instead of an iris that opens (larger aperture, more light gets in and less depth of field) and closes (smaller aperture, less light gets in and more depth of field) in increments, they might have only 2 preset aperture settings.

With a large enough aperture, you could shoot on a cloudy day without the use of flash. You could shoot action pictures using a fast shutter speed. You could shoot portraits and throw the background out of focus. If the maximum aperture is small to start out with, you can only shoot in a limited range of lighting situations, and would be overly relying on the flash to provide enough light to properly expose your shots. You would be using slow shutter speeds which means that action shots without flash would be impossible. Slow shutter speeds also mean that any movement on your part results in blurred pictures.

Note: a "large" aperture is represented by a small number (e.g. F2.8), while a "small" aperture is represented by a large number (e.g. F16).

Shutter speed is the length of time your camera's shutter stays open to let light in. Digital cameras usually come with a range of possible shutter speeds.

Note: 1/2000th of a second allows half as much light to hit the camera sensor as 1/1000th of a second, so you want very fast shutter speeds for bright subject, and slow shutter speeds for night shots. (ISO settings will help - the higher the ISO, the more likely you can hand-hold a night shot.)

Your camera relies on the combination of aperture and shutter speed to determine proper exposure. So if you have a wide range of shutter speeds, you have more latitude in deciding what aperture to use and what kind of pictures you can take.

One of the other main concerns when choosing the shutter speed variability is the control of camera shake; a shutter speed of 1/30th of a second or faster allows you to hand-hold the camera; slower shutter speeds require a tripod, or else the final image will appear blurry.

Bottom line: ensure that your digital camera provides a full range of shutter speeds ranging all the way from fast (e.g. 1/1,000 sec.) to slow (1 sec. or more).

(Only available on non-SLR cameras)

A viewfinder is the external LCD device you look through to compose your image. Some cameras allow this mini-screen to pull away - or "flip-out" - from the body of the camera.

The whole display can be folded in when not in use, thus protecting the screen, then flipped out and used either in the 'out' position (tilted up or down) or inverted and folded back against the rear of the camera just like a conventional digital camera.

If you frequently take photos with the camera on the ground, viewfinders that flip-out allow you to flip the viewfinder parallel to the ground and avoid crawling on the ground to line up the shot. The tilt also allows you to angle the viewfinder out of the sun - all viewfinders suffer from poor visibility in bright daylight.

The most popular types of flash memory cards for use in digital cameras are: Secure Digital (SD), CompactFlash (CF), Memory Stick (MS), MultiMediaCard (MMC) xD-Picture Card (xD) and SmartMedia (SM).

Volume of storage (MB or GB) will depend on your camera's megapixel resolution, and the maximum number of photos you plan to take before having access to a computer for download. For example, if you're going away for 3 weeks to Italy without a laptop, you should consider purchasing or borrowing additional cards, or get one large one. I know my 2GB card in my 8mp camera won't last me more than a week without download, but I love snapping photos!

The type of memory card you use is dictated by which digital camera you buy. These physically different cards are -not- interchangeable. So if you already own a camera/card reader - or know someone whose memory cards you might want to borrow or swap - be aware of which storage type you need to buy.

Check out Steve's Flash Memory Card reviews for more information.

Here's a general rule of thumb for what size of card to get (assuming you take fewer photos than I do!):

- at least 128MB for a 3 megapixel digital camera
- at least 256MB for a 4 megapixel digital camera

The reason that 'bigger is better' is because it's a real bother to change film or memory card (it usually happens when things just start to get interesting around you) and you risk missing a good picture.

Check out my Links page for my favourite Camera Review web sites.

For further assistance picking the right camera for you, check out this ebook: Choosing your Camera and Accessories