CCDDigital cameras don't use film, instead they record images on an electric light sensor called charge-coupled device (CCD), which is made up of millions of tiny points called Pixels. The CCD is a solid-state chip that turns light into electric signals. CCD cameras are light-weight, require little power (so the batteries are light as well), are inexpensive. The CCD "sees" what a frame of film in a traditional camera sees through the lens with the shutter open. The light collected by the CCD is then converted into data and this data is then stored on the camera's memory card.
Advantages
The image can then be viewed on the camera's display screen, downloaded onto a computer, edited, stored and also printed in photographic quality.
There is no need to buy additional memory to take more photos as you can reuse the same memory over and over again, just as you do with the memory in your computer. You can also view the image you have just taken and if you're not happy with it you can delete it, leaving space for another one. Once an image is downloaded from the camera to the computer, it is then possible to use image editing software, included with most digital cameras, to adjust brightness, contrast, color levels, sharpen images and even apply special effects. The images can be sent to friends via email, uploaded to websites for public viewing and printed in the same photographic quality that you would obtain from a traditional film camera.Pixels
A pixel is the smallest piece of information that a digital image is made from. The image can't be broken down to a smaller point than a pixel. Your computer monitor has pixels. A fifteen inch monitor with a standard screen resolution of 640 x 480 pixels and a 17 Inch monitor at 800 x 600 pixels. Modern digital cameras can record images in resolutions up to 2048 x 1532, which is over 3 Million Pixels (3 Mega Pixels), making the image much larger than most computer monitors and resulting in the need to scroll the image across the screen. A camera's CCD is also made up with pixels. On a CCD each pixel is actually a tiny light sensor that can detect light and color levels.
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Here is very simple example of a cameras CCD , it has a resolution of 12 x 12 = 144 pixels. Each red dot that makes up the man is 1 Pixel.
Because the resolution is so low the image has very limited detail.
Print Sizes
The maximum print size that a digital camera can produce is directly related to the number of pixels on the cameras CCD (the resolution).
A 1.3 Mega Pixel Digital Camera, produces a screen size image of 1280 x 960 and can print in sizes up to
5 x 7 inches in photo quality.
A 2.1 Mega Pixel Digital Camera, produces a screen size image of 1600 x 1200 and can print in sizes up to
8 x 10 inches in photo quality
A 3.34 Mega Pixel Digital Camera, produces a screen size image of 2048 x 1536 and can print in sizes above
8 x 10 inches in photo quality. Two Digital Cameras toped all the rest in the cover story of September 2nd issue of PC Magazine Review
5.0 megapixel, $600 list. 800-877-0155
3.1 megapixels, $329 list.800-235-6325
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HP Digital photography for your business. Free. To access the lesson, log on to the