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Digital cameras have revitalised photography as a hobby. Because digital cameras record images on reusable memory cards instead of film, there are no developing costs, so you can take as many pictures as you want and only print the ones you like. Picking the right camera for your needs can seem a bit daunting, but this guide will help you make the right choice by giving you the information that is important to you.
Overview
Because digital cameras record images on reusable memory
cards instead of film, there are no developing costs, so you can take
as many pictures as you want and only print the ones you like. Most digital
cameras feature an LCD viewfinder that lets you perfectly compose your
photo and then check any photos taken. Because the images are stored as
standard digital files, your computer becomes your darkroom, letting you
crop, enlarge and retouch your photos to perfection. To share your photos,
you have numerous options. You can e-mail them to friends or post them
on a photo-sharing website. If you want prints, you can use an online
photofinisher or create them at home on a photo printer.
When shopping for a digital camera, start by identifying your needs. Will
you primarily be viewing your pictures on a computer screen or do you
plan to make a lot of prints? Will you be using the camera for professional
graphics work? Will you want a zoom lens? Are there specific features
you require, such as macro ability or movie mode? Knowing what kind of
photos you'll be taking most often will help you decide what resolution,
storage type, power source, and other amenities you'll need. See the specific
features below for more details.
Resolution is one of the most important ratings of a digital camera. Digital images are made up of dots called pixels. Resolution refers to how many pixels make up a photo, and it is usually measured in the horizontal by vertical resolution, as in "1,280 x 960", or as a total, as in "1.2 megapixels" (meaning 1.2 million pixels). The higher the resolution, the sharper the picture. Today's digital cameras generally range in resolution from 640 x 480 (0.3 megapixels) to 2,560 x 1,920 (5.25 megapixels) although much higher resolutions are available for professional use. Common digital camera resolutions include 2,048 x 1,536 (3 megapixels), 1,600 x 1,200 (2 megapixels), 1,280 x 960 (1.3 megapixels), 1,024 x 768, and 640 x 480.
The resolution you need depends on what you plan to do with your photos. If you just want to e-mail photos to your friends or put them on the Web, you may be happy with a low resolution such as 640 x 480. If you want to print your photos, however, plan on having at least 150 or more pixels per printed inch. If you try to print lower-resolution images at larger sizes, the results tend to look grainy, blurry or blocky. Most cameras also offer the option of taking lower-resolution photos so that you can fit more photos in the camera's memory.
Here's our approximate
guide to maximum print size by resolution (based on prints at 150 pixels
per printed inch): 0.3 Megapixels (640 x 480) = 4 x 3" print
1.2 Megapixels (1280 x 960) = 7 x 5"
print
2 Megapixels (1600 x 1200) = 10 x 8" print
3.2 Megapixels (2048 x 1536) = 13.5 x 10" print
4 Megapixels (2288 x 1712) = 15 x 11" print
5 Megapixels (2500 x 2000) = 17 x 13" print
Another factor that affects image quality is compression, the process that shrinks a photo's file size. Most cameras take photos as compressed JPEG files, which allows you to store more images on a memory card. Compression also makes it faster to save and download photos and easier to e-mail photos or download them as part of a website. For most uses compressed images are adequate. Compression causes a small amount of data loss, however; if you need the absolute best-quality images for professional use, consider buying a camera that takes uncompressed photos. You'll only be able to fit a few uncompressed images on a memory card, but you'll get the sharpest, clearest, most-detailed pictures possible.
Memory, the equivalent of film in a conventional camera, is where pictures are stored as you take them. A camera's memory size will determine how many images you can store. If you anticipate downloading your images often, a camera with a large amount of memory isn't as important. But if you plan on taking many pictures without having access to your computer for downloading, you should buy a camera with a lot of included or expandable memory--or plan to buy an extra memory card.
Cameras with internal memory store their images in a non-removable memory chip embedded within the camera. However, most consumer cameras use external memory, generally in the form of a reusable memory card that you can remove when it is full. Common types of memory card include CompactFlash, SmartMedia, SD (Secure Digital), Memory Stick and xD. You can increase the number of photos you can take by buying additional cards.
Most digital cameras come with enough memory in the box to take from 12 to 36 shots at full resolution--about the same as one roll of film for a traditional camera. Unlike the film-roll however, the memory card can be reused once your pictures are safely stored on your computer, making digital photography a very cost-effective way of taking pictures. Also, larger capacity cards can give easily be used on most cameras, often providing storage for many hundreds (or even thousands) of photos at a time.
The actual number of pictures that can be stored on a memory card varies from camera to camera and depends on a selection of factors including compression settings, storage formats and image complexity. Bearing this in mind, the table below attempts to indicate the approximate quantity of images that can be fitted on to various sizes of memory card, based on average file sizes and common compression ratios.
Digital cameras use significantly more power than traditional cameras. While typical cameras usually need their batteries replaced every 15 rolls of film or so, you might find your digital camera running out of batteries before you've filled its memory, especially if you use the LCD all the time. Digital cameras use either a rechargeable battery pack or traditional batteries; some come with an AC adapter as well. Consider buying an extra battery pack or investing in rechargeable batteries and always have extras on hand.
Most digital cameras come with at least an optical viewfinder--the kind you look through on traditional film cameras--but many digital cameras also come with an LCD screen built into the back. The LCD screen is especially useful because you can see what your picture will look like before you take it. It also allows you to look at the photos you've already taken. Some cameras even let you display pictures on the LCD screen in thumbnail format, usually nine or 12 to a screen. Most cameras also let you select pictures to erase; this handy feature gives you the chance to edit out the photos you don't want in order to free up memory. As mentioned above, using the LCD screen is a significant battery drain, so if you use it often, have extra batteries on hand.
The length of a camera's lens determines how much of a scene will fit in a picture. Lens lengths vary between wide-angle (used for landscapes and shots in which you want to include as much as possible) and telephoto (used for close-ups and to zoom in on faraway objects). "Normal" lenses, about 50 mm on traditional cameras, most closely approximate what your eye sees; anything shorter than 50 mm is considered wide-angle, while anything longer is usually considered telephoto.
The image sensor in digital cameras is smaller than the surface of a 35 mm negative, so lenses on digital cameras tend to be much shorter than on traditional cameras. Look for the "35 mm equivalent" rating to get a better idea of a camera's range. Most fixed-length lenses on digital cameras fall somewhere between wide-angle and normal focal length. Many digital cameras now offer zoom lenses, which take you from wide-angle to telephoto. In addition to this optical zoom capability, some cameras provide digital zoom, which is nothing more than software in the camera that crops the edges off of your image and blows up the remaining information to the size of the original. While digital zoom adds extra close-up power, this comes at the expense of resolution. We recommend getting a camera with an optical zoom. Some cameras also have macro capability, which lets you focus very close and take pictures of small objects--useful for taking photos of flowers, jewellery and so on.
Most digital cameras come with some form of zoom facility. This allows you to move from wide-angle (ideal for landscapes for example) to telephoto (for close-ups). Clever use of zoom facilities can really improve your pictures, allowing you to perfectly frame portraits or get closer to the action when this might not be physically possible.
There are two types of zoom used on digital cameras--optical and digital--both of which are rated by how many times "larger" they can make a distant object. "3x optical, 5x digital" on a camera's specifications, for example, means that a camera's optical zoom can magnify by a factor of three, with the digital zoom providing a magnification of five--in combination providing a maximum theoretical magnification factor of fifteen times.
When using an optical zoom, the camera's lens does all the hard work, increasing or decreasing the apparent size of your subject in your picture in much the same way as a pair of binoculars. A digital zoom, on the other hand, is nothing more than software in the camera that crops the edges off of your image and blows up the remaining information to the size of the original. This method has limitations however, with the extra close-up power this provides coming at the expense of resolution. This can be a particular problem on cameras with a relatively small megapixel rating, as images can become slightly blocky and lacking in detail. We recommend getting a camera with an optical zoom, using this as your primary means of magnification and only resorting to the digital zoom when you require extra magnification, as this will help keep your pictures as crisp and sharp as possible.
Fixed-focus digital cameras have a non-moving lens that is preset to focus at a certain range. Higher-end digital cameras usually have autofocus instead, which automatically focuses the camera at your subject's distance.
Most cameras automatically determine the correct exposure for the lighting conditions. Sometimes, however, the scene will appear too dark or too washed-out. In these cases, it's handy to have a digital camera that offers manual exposure compensation, allowing you to set the exposure a few stops brighter or darker. A digital camera's ISO-equivalent rating lets you know how light sensitive it is; a camera rated ISO 100, for example, has about the same light sensitivity as a traditional film camera loaded with ISO 100 film. Higher ISO ratings mean the camera is more sensitive to light and can take pictures in darker settings.
Digital cameras work just like traditional cameras when it comes to aperture: the maximum aperture rating of a camera lets you know how much light it can let in. Aperture ratings represent ratios; the lower the aperture rating, the more light sensitive the camera is and the better it can take photos in low light.
Most digital cameras come with a built-in flash. Basic flash modes should include automatic (senses when to use the flash according to lighting conditions), on (for all photos), and off. Some cameras include additional features, such as red-eye reduction or night portrait mode. Red-eye reduction is ideal for photographing people or animals--it fires a series of short flashes before the final flash and exposure, making your subjects' pupils contract and preventing them from having glowing red eyes in the final photo. Night portrait mode sets your flash to go off at the beginning or end of a long exposure, letting you take portraits set against a night scene, such as a cityscape. However, you should find something steady to set the camera on; the long exposure needed for low light will turn any shake of the camera into a blurry spot in your image.
A self-timer sets your digital camera for a delayed exposure, usually giving you about 10 seconds before it takes the picture. This feature is useful for getting yourself in the photo and can also be used to take low-light photos, preventing the camera shake caused by pushing the exposure button.
A few digital cameras have the ability to record a few seconds of audio with each shot, letting you add a personal sound bite to your photos. This feature tends to eat up battery power rather quickly, so if you use it often, be prepared with extra batteries.
Many digital cameras now include movie mode, a feature that lets you take short film clips with your camera. To keep from instantly filling your memory card and overwhelming the camera's processor, the movie's resolution is usually much lower than the camera's maximum resolution, and the total length is typically limited to 10 to 90 seconds. It won't replace your camcorder, but it's a fun additional feature. Some models will record movies with sound, and some will only limit the length of the recorded clip based on the size of memory card installed.
The first digital cameras were heavy, clunky boxes that could hardly be called stylish. But today's digital cameras are on a par with the sleek, lightweight form of traditional point-and-shoots, and many feature stainless-steel casings for added durability.
Some digital cameras include a video-out function that gives you the option to hook them up to a TV to display your pictures. With this feature, you can also record your pictures onto a VHS tape.
Most high-end cameras include software and connections for both Mac and PC computers, but make sure the digital camera you want is compatible with your platform before you buy it. All consumer digital cameras come with the software you need to download your pictures onto a computer. Also, most will include image-editing software--which lets you crop, adjust, or add special effects to your photos. The software supplied is not always the best you can get, so you may want to consider investing in a separate image-editing application.
Digital cameras can use a variety of different interfaces. Most use a USB interface, which plugs into a port on the back of your computer and the required cables are normally included in a digital camera package. Others come with a PCMCIA interface, which can be inserted directly into a notebook computer. Certain cameras use 3.5-inch floppy disks as memory or provide a floppy-drive adapter for the memory cards. Another way to download images to your PC is via a memory card reader.
Once you've downloaded and edited your images, most e-mail programs will let you attach them to messages. You can also upload them to your website or copy them onto a floppy disk or CD-R to give to your friends and family. Some colour printers have slots that accept a camera's memory card and let you directly print your photos; otherwise, you can use the printer hooked up to your computer. One of the advantages of using a digital camera is that you can make copies of your photos whenever you want, without having to hunt through negatives and send them out for processing at a lab. You can also make calendars, greeting cards, collages, and enlargements easily and inexpensively at home.
