Before going on to buy a camera you need to decide on why you need the camera and based on the purpose one can choose from the following main three types:
Point and shoot-reasonably compact, with features and size like 35mm cameras.
Lifestyle- with moderate features, its sleek and compact, so you can carry it around with ease.
Professional with interchangeable lenses, flashes and other accessories, this camera is robust and feature laden, just the right choice for a professional or serious photographer.?
Maximum resolution is one of the most important ratings of a digital camera. Digital images are made up of dots called pixels. Pixels are the tiny dots on any digital image that combine together to make up the image. The resolution is measured in the horizontal by vertical resolution, as in “1,280 x 960,” or as a total, like “1.2 mega pixels” (meaning 1.2 million pixels). With the increasing number of pixels in your image, the quality of the image improves to give a sharper picture. Higher resolution images will enable you to enlarge your image to higher pixel dimensions without leading to a pixilated (broken) image. The resolution you need depends on what you intend to do with your photos. If you plan to e-mail photos to your friends or put them on the Web, a camera with a lower resolution like 640 x 480 would be fair enough. If you try to print lower-resolution images at larger sizes, the print tends to look grainy, blurry, or blocky. Mega pixel cameras often offer the option of taking lower-resolution photos so that you can fit more photos in the camera’s memory.
The process that shrinks a photo’s file size is called compression. This is another factor that affects the image quality to a great extent. Most cameras take photos as compressed JPEG files. These compressed images allow you to store more images on a memory card. Another benefit of compression is that, it is faster to save and download compressed photos and easier to e-mail photos or download them as part of a Web site. For most uses like, e-mailing photos to friends, printing out photos for albums, or posting images on the Web, compressed images are enough.
However compression causes a small amount of data loss. For those who need the absolute best-quality images, it is better to buy a camera that takes uncompressed photos. However in this case you’ll only be able to fit a few uncompressed images on a memory card. Undoubtedly this will give the sharpest, clearest, most-detailed pictures possible.
Memory is the equivalent of film in a conventional camera. It is the place where pictures are stored as and when you capture them. A camera’s memory size will decide the number of images that can be stored. If you can download the stored photos often, buying a high memory camera is useless or rather a waste of money. Except 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 either have internal memory, memory card slots or both Cameras with internal memory store their images in a non removable memory chip embedded within the camera. However, most consumer cameras use external memory i.e. a memory card like CompactFlash, SmartMedia, and Memory Stick that are all common types or even a floppy disk–which you can remove when it’s full. You can increase the total number of photos you can take by buying an additional external memory. Most digital cameras come with enough memory to take from 12 to 36 shots at full resolution just about the same as one roll of film for a traditional camera.
The types of memory cards are important because this will tell you what type of memory card are needed to expand on the existing internal memory. The size of the memory needed in different situations will be as follows.
128MB: Good enough if you want to use the camera mostly at a social do or a party.
512MB to 1GB: On a vacation abroad when you probably won’t get a chance to download images for a number of days at a stretch.
Most digital cameras come with at least an optical viewfinder ie 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 (Liquid Crystal Display) screen allows the photographer to view the picture he/she has taken straight away to check if the picture needs to be retaken which you can use as a viewfinder as well. The LCD screen is especially useful because you can see what your picture will look like before you take it. Using the LCD screen is a significant battery drain, so if you use it often, you need to have extra batteries in hand.
For a digital camera, they vary from 1.5-2.5 inches.
It is the length of a camera’s lens that 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 fit in content as much as possible and telephoto used for close-ups and to zoom in on faraway objects. “Normal” lenses, about 50mm found in traditional cameras, most closely approximate to what your eye sees; anything shorter than 50mm is considered wide-angle, while anything longer is usually considered telephoto. The image sensor in digital cameras is generally smaller than the surface of a 35mm negative, so lenses on digital cameras tend to be much shorter than on traditional cameras. Look for the “35mm equivalent” rating to get a better idea of your camera’s range.
This enables the photographer to zoom in on an object without any problem in picture quality. Depending on the magnification number, you can zoom in more. For a digital camera, the optical zoom is on average 3.0-5.0 (odd cases of special digital cameras have an optical zoom of 6.0-10.0,).
This feature enables the photographer to zoom in on the centre of the picture by removing the edges of the image. However, depending on the MP resolution of your camera, the image can become fuzzy. Digital cameras can easily vary on average from 2.0-8.0 and the same can be the range for the SLR Professionals, except some will exceed 8.0. The higher the zoom the better the camera.
Focus an exposure
There are some fixed-focus digital cameras that have a non movable lens that is preset to focus at a certain range. Higher-end digital cameras usually have auto focus instead, which automatically focuses the camera at your subject’s distance. In most cameras, the correct exposure for the lighting conditions is automatically determined. However sometimes, the scene will appear too dark or too washed-out. In such cases, it’s better to have a digital camera that offers manual exposure option, which allows you to set the exposure a few stops brighter or darker according to your need. In a digital camera, its ISO-equivalent rating lets you know how light sensitive it is. A camera rated ISO 100, for example, has approximately the same light sensitivity as that of a traditional film camera loaded with ISO 100 film. Higher ISO ratings mean that the camera is more sensitive to light and is potential enough to take pictures in darker settings.
The aperture in digital cameras work just like those in traditional cameras. The maximum aperture rating of a camera is the maximum light it can let into the camera. Aperture ratings is inversely proportional to the sensitivity of light ; the lower the aperture rating, the more light sensitive the camera is and the better it can take photos in low light.
Audio and Movie capture
This feature allows you to record sounds and moving images at the same time, in exactly the same way that a camcorder functions. Some cameras even come with a facility that enables them to play the video footage on TV from the camera.
Some digital cameras provide the facility to record a few seconds of audio with each shot, thus letting you add a personal sound bite to your photos. However this feature tends to eat up battery power rather quickly, so if you have to use it often, you should be prepared with extra batteries.
Many digital cameras now include movie mode too. This is a feature that lets you take short film clips with your camera. To avoid instantly filling your memory card and overwhelming the camera’s processor, the movie’s resolution is usually kept much lower than the camera’s maximum resolution, and the total record length is typically limited to 10 to 90 seconds. It won’t substitute your camcorder, but it’s an additional feature that sure helps you a lot and is fun to have.
More power is used by digital cameras than by traditional cameras. Typical cameras usually need their batteries replaced after every 15 rolls of film or so. However in digital cameras you might run out of batteries even before you have filled its memory. This happens mainly if you use the LCD all the time. Digital cameras generally use either a rechargeable battery pack. Sometimes traditional batteries are also used, while sometimes they come with an AC adapter as well. To be on the safer side, consider buying an extra battery pack or investing in rechargeable AAs, and have extras on hand. Battery life has improved tremendously since the early days of digital photography, but limited battery life is still one of the biggest problems with digital cameras.
Most digital cameras come with an in-built flash. Basic flash modes should include automatic on and off based on the lighting conditions. Some cameras however include additional features, such as red-eye reduction or night portrait mode. Red-eye reduction is perfect for photographing people or animals–it fires a series of short flashes before the final flash and exposure, thus making the 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. Thus it lets you take portraits set against a night scene
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 create space in the memory.
A self-timer allows your digital camera for a delayed exposure, usually giving you about 10 seconds before the picture is taken. This feature is useful to click yourself in the photo and can also be used to take low-light photos. Thus preventing the camera shake caused by pushing the exposure button.
Most high-end cameras have software and connections for both Mac and PC computers. However I is necessary to 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.
This feature enables the photographer to capture still images of something moving very fast. The camera is able to freeze the picture within those milliseconds of time to create a clear quality picture image. You can also use this feature in low light conditions.
Nowadays you can buy special printers, depending on the compatibility of your camera, to print off your pictures without connecting it to a PC. This applies both for digital and SLR Professional cameras.
Size / Portability
Size is another very important factor to consider. If you are to use the camera for non professional purposes the size has to be small as you cannot afford to carry huge sized cameras when you are enjoying a trip