How a Compact Digital Camera Works

"I want to explain how the compact digital camera works as compared to a film camera. In a film camera there is actually a physical piece of film that runs along the back of the camera, and that's what captures the light. But in a compact digital camera, there is a sensor. It's usually called a CCD sensor or SMOS sensor. It's about the size, usually slightly smaller than a film negative. It's covered in a light-sensitive material, which is made up of these tiny little pixels. That's where you get, when people start talking about mega pixels or resolution, that kind of thing; they're talking about how many pixels are making up this sensor. For example, this camera has 7.1 megapixels, or million pixels. The main thing with the pixels is it affects the resolution. Resolution becomes more important when you're actually printing an image as opposed to using it on the web, because the way that a monitor works, there is a lot more forgiveness, and an image can look good with only, like a lot of pictures that are sized for the web are only at 72 dpi or ppi. Dpi means dots per inch, and that's usually a term referred to printing because that's how many little tiny dots make up the printed image. Or ppi is pixels per inch, and that's on a screen or anything digital that displays how many pixels actually fill up a square inch. When you're printing something it's really important that your resolution to get a really sharp, good quality picture is at 300 dpi. That's the industry standard, whether you're having your image printed in a magazine, or whether you're just going to take it to the corner and have it printed at your local photo finisher."