Digital Camera

A digital camera is a photographic device that can take both still and moving pictures without the use of conventional film. Unlike normal cameras, the digital camera does not rely on mechanical and chemical processes but records images on a light sensitive sensor.

Digital cameras have a built in computerised system that records images in an electronic form. Today most compact digital still cameras can record moving video and sound as well as still photographs. Indeed these new cameras are so good that there normal 35mm film counterparts are quickly becoming obsolete.

Digital cameras are battery operated and even this technology is improving quickly and today the batteries store a lot more energy. They include features normal cameras cannot possibly match including displaying an image on the camera's screen immediately after it is recorded, they also have the capacity to take thousands of images on a single small memory device, as well as an ability to edit images, record video and sound, the ability to transfer the images into another storage system and the subsequent deletion of images from the cameras memory device allowing it to be reused over and over again without the added cost of normal cameras which have to purchase new films when full.
Since the images that a digital camera captures is in electronic form they use sensors to read the light intensity and convert it through a colour filter and digital memory device to store the data of the digital image either in a mode called RGB (RGB is shorthand for Red, Green, Blue) colour space or as raw data. There are two main type of digital camera sensor, one is called a CCD (chain coupled device and the other is called CMOS (complementary metal oxide semiconductor).

A collection of tiny diodes, the CCD gathers electrons when they are struck by photons or the light particles. Each diode or photosite is sensitive to light, meaning that the brighter the light, the number of the electrons gathering will be larger

The main quality of a digital image is measured in pixels. In digital cameras the pixel count is usually measured in mega pixels. The more mega pixels a camera have usually the better quality the image will be. But other factors also play a big part in image quality. Similar to conventional cameras, a digital also uses a series of lenses that focus the light and creates the image that you want to capture. In a conventional camera they focus light onto a film while a digital camera focuses the light into a semiconductor device that electronically records the light.

Digital cameras are incorporated into many devices including mobile phones, personal data assistants (Pad’s), and things like space telescopes such as the Hubble space telescope which is in essence a specialised digital cameras.

Although digital camera’s where initially expensive to manufacture, as the technology has progressed the actual costs have gone down and the specifications have just got better and better. When buying a digital camera there are certain aspects to consider. First is what exactly do you want to use your new digital camera for? If you want to be a professional photographer then you will need to go for a high end camera. But if it is only for taking family snaps and such then there are plenty of great compact digital cameras on the market that will suit your needs and budget.

Some features you may want to consider are a good LCD screen to view your pictures after you have taken them. A timer, built-in flash, time/date stamp, and optical zoom. All of these features are usually standard but some have better specs depending largely on your price range. However the key features you should check and compare to get the best digital camera for your needs are:-

Image quality. The resolution is the one most important quality you need in a digital camera. The better resolution you have, the more you can enlarge your images without removing clarity or that out-of-focus effect. Your camera builds images are built from tiny blocks of colour (pixels) so the more pixels you have in a small area the better the resolution of the picture will be.

Lens. Most digital cameras have both digital and optical zoom. A higher optical zoom is always better than a higher digital zoom. Digital cameras are usually furnished with optical of between 3x to 10x. The better the optical zoom, the higher it climbs up to the best digital camera category. Digital zoom of the camera will enable you take the pixels from the image sensor and incorporate them into your image.

Memory. Always make sure that your memory card is the right one for your digital camera. There are different types of memory card like the XD SD, Flash card and the likes if you’re a photo freak, be sure that you have enough memory to take all the images you can. The last thing you need is to run out of memory at an important moment. Think 512MB or 1GB if you’re a photo junkie and carry a spare memory card in case your digital camera runs out.

Computer Interface. A digital camera captures images and you can transfer them to a host computer using a digital interface, always make sure that it is compatible with your PC, laptop, palmtop or whatever your local picture printer software is. Today most computers are compatible with most forms of digital camera, but there is no harm in making sure before you buy your camera just in case you run into a problem.

Physical properties. If you travel a lot or use your camera in harsh conditions, choose a handy and portable digital camera that’s up to the job. Your camera should be shockproof to a certain degree, waterproof or water resistant (there is a difference), in certain conditions like in snow you may also need a freezeproof camera. Pressure and crush resistance is also good to have. If you want to take underwater pictures then choose a camera which can be housed in an underwater casing and check the depth your camera can work at.

Options. Most digital cameras have the standard options we mentioned earlier. However if you want a state of the art camera that is as up to date as can be then you want the best options you can afford. Anti blur or image shift stabilization is one great new option that compensates for camera shake. Crystal LCD which has better image display, face detection abilities, shadow adjustment technology, Bright capture technology allows you to shoot in the dark and clearly preview your image are just a few options to consider before buying your new digital camera.

These are just some of the basic to look for before buying. Before making your choice as to which digital camera best suits your needs have a read of the many revues online, and there are also some great magazines for digital cameras that will give you great comparison charts.


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