Digital Cameras

Colter Freund

All a digital picture really is, is a collection of millions of tiny little squares called picture elements (pixels) that are put in order to form a picture, like a puzzle. The computer divides the page into a grid of pixels and uses numbers to tell the screen exactly what shade of colour to use.

Once digital pictures are taken, they are stored safely inside the camera. You can just hook up the camera to the computer and change the picture however you want, send them over the internet, or even put them onto a web page. You can also see the picture on a small screen on the camera.

A digital camera has a lense to let in the light from an image to focus it. An aperture is a hole that can be made smaller or larger to let in more or less light, depending on the condition. This then puts the image on the “film” or exposure and creates a picture and stores it in the camera.

The first delay, which is the time it takes between pressing the button and capturing the image, is called the refresh rate. This happens because the camera has to clear the image sensor, set white balance to correct for colour, set the exposure, and focus the image. The second delay is the recycle time, which occurs when the captured image is processed and stored.

During compression, data that is duplicated or which has no value is eliminated or saved in a shorter form, greatly reducing a file's size. When the image is then edited or displayed, the compression process is reversed.

Using lots of compression. Using little compression.

Zoom lenses come in two varieties; optical and digital zooms. An optical zoom lens actually changes the amount of the scene falling on the image sensor. A digital zoom lens uses a movement of your hand hand by taking a part of the normal image falling on the sensor and then saving that part.

The lens' job is to sharply focus the scene onto the surface of the image sensor. Most of the time, lenses made from glass are sharper and more damage resistant than lenses made from plastic. Generally lenses made by a name company with a long tradition of making lenses such as Nikon are considered the best.

When photographing people, you'll often see images with what's called red eye. The light from a flash has entered through the subject's pupil and reflected off the retina at the back of the eye and then back out to the camera. Some flash units have a red-eye reduction mode.

For electronic devices it is better to use NiMH batteries than NiCad batteries. NiCad batteries use Cadmium, a highly toxic heavy metal, that can damage the environment if not disposed of properly. NiMH batteries usually have a higher capacity than NiCad batteries of the same size.

Some cameras have built-in microphones that let you speak into your camera. These recordings are saved in sound files that can later be played back and edited on the computer.