What to look for in a digital camera

Selecting a digital camera is not very different than picking a 35mm autofocus camera. You first need to ask yourself what type of photography you intend to do and what you want to do with your pictures. Just as in 35mm where you have interchangeable SLRs, point and shoot and zoom lens reflex (ZLR), digital cameras offer the same, except they don't use traditional films. By far, interchangeable digital cameras are the best choice for serious photography. You can select lenses for a wide variety of subjects and have access to powerful flash units and other accessories. Digital point and shoot and digital ZLR cameras are fine for snap shooting or traveling, although I must admit that some ZLRs are excellent full featured models that can seriously rival interchangeable models. Lets look at what is important and features you need to look for.

Resolution is the first thing you should look for in a digital camera. Unlike film cameras where film is used, digital cameras use a CCD light sensitive chip that records the image. Think of CCD as film used in traditional cameras. A film camera records the image on film which is sensitive to light. Light passes through the lens and exposes the film. Slow fine grain films produce sharper more detailed images. More resolution does the same in digital cameras.


Left Image: Digital Camera Sensor


Resolution is the number of pixels on CCD. More pixels on the CCD mean a higher resolution image. More resolution allows you to make larger prints with more detail. Digital camera's resolution is referred to as megapixels. To make prints, 300 pixels or dpi (dots per inch) is enough. Lets say you normally make 8X10 prints. You need 2400 x 3000 (8 x 300=2400 and 10 x 300=3000) pixels to produce a high quality print. Multiplying pixels gives a total CCD resolution of 7.2 megapixels. In order to make 8 x 10 prints, you need to look for a camera with at least 7 megapixel resolution. If you plan on making smaller prints, there is no need to pay more for more megapixels.

The next thing you need to look for is the lens or lenses that can be used on your camera. If you currently own some lenses for your 35mm SLR, you should look for a digital camera that accepts these lenses. There is no need to switch your whole system to upgrade to a new digital camera.


Although some lenses are specifically designed for digital SLRs, most 35mm lenses will work on digital cameras as well.




Digital zoom cameras have built-in lenses such as 10X optical zoom and digital zoom. 2X and 3X are the most common optical zooms. A 3X means three times from the widest to longest setting, for example, 35mm to 105mm. The equivalent for 35mm lenses start at around 35mm and moves up to telephoto depending on the power of the lens. You get more magnification by using digital zoom. The problem with digital zoom is loss of quality. What happens is a portion of the actual image is magnified which will reduce sharpness greatly. My advice is to avoid digital zoom for best possible quality.

The LCD on the back of digital cameras is an awesome feature. You can view and preview images on the LCD panel and decide whether to keep the picture or throw it away. This is one feature that gives digital cameras an edge over other formats. Images are stored on digital media which are reusable many many times. If you don't like a picture, just erase it or download it to your computer if you are happy with the result. No need to purchase film and pay for processing. Once you are done, erase all the files, reload and start shooting again.

Flash memory is used on most digital cameras and are sold as SmartMedia, CompactFlash, and Sony's MemoryStick. Think of these flash memory cards as Fuji or Kodak films, except they are for digital cameras. There is no real difference as far as capturing images are concerned. SmartMedia and CompactFlash cards are used by most cameras, while Sony offers MemoryStick. All are very much alike and come in variety of storage capacity. Some cameras also accept IBM Microdrives which offer storage capacity up to 1 GB compatible with Type II CompactFlash slots. You'll need high capacity cards for high resolution images. More capacity costs you more, a lot more. However, you only pay once for flash memory and can re-use it many times. Sony makes or made digital cameras that use mini CDs instead of flash memory. Images can't be erased but the cost of CDs are very little.


CompactFlash Cards

File types are another feature to look for. JPEG, RAW, and Tiffs are the most common files to save your images. JPEG compress the image to take up less space. The draw back is loss of image quality. RAW and Tiffs are used for best image quality but more storage is required which takes longer for the camera to store images. A JPEG file of 3 million pixels for example, is 1MB file, while a Tiff is 9MB. More sophisticated cameras offer RAW option. RAW is smaller than Tiff, but gives more accurate image data.

Other features are very similar to 35mm. Exposure modes, viewfinder information, exposure compensation, and flash capability are some important features in digital cameras. Burst rate is important in wildlife and sports photography where fast recycle time is essential. Digital cameras "write" the image file which can take a few seconds to do. Top end cameras solve this problem by adding RAM to the camera. This way it is possible to take several shots without having to wait. Autobracketing is another useful feature. It gives you three different exposures of the same shot so you can be assured that at least one will be properly exposed. Most digital cameras offer multiple-sensitivity setting ranging from ISO 100 through 400 and in some models even higher. Higher ISO is used under low light and for fast action photography. Just as grain in 35mm is increased with faster films, digital cameras get "noise" when set to high ISO settings. Two more unique features are Movie Mode that record clips from 10 second to five minute with sound, and Stitch Mode that shoots multiple images for panoramas.

Buy a model that gives you the resolution you require and have all the features that you feel is essential for the type of photography you do.