Fundamentals of Digital Images & Photography

Pixels & Colors The pixel (a word invented from "picture element") is the basic unit of programmable color on a computer display or in a computer image. The specific color that a pixel describes is some blend of three components of the color spectrum – Red, Green, & Blue Simulation:

How to Take a Picture in Automatic Mode 1. Turn the camera on and set it to automatic mode. 2. Compose the image in the viewfinder or on the monitor. 3. Press the shutter button halfway down so the camera can set focus and exposure. 4. Press the shutter button all the way down to take the picture. 5. The camera then saves the new image onto the camera's memory card. 6. When done, turn the camera off.

How an Image is Captured Digital cameras, like earlier cameras, have been basically black boxes with a lens, an aperture, and a shutter. The big difference between traditional film cameras and digital cameras is how they capture the image. Instead of film, digital cameras use a solid-state device called an image sensor, each of which captures a single pixel in the photograph to be. When you take a picture the shutter opens briefly and each pixel on the image sensor records the brightness of the light that falls on it by accumulating an electrical charge. The more light that hits a pixel, the higher the charge it records After the shutter closes to end the exposure, the charge from each pixel is measured and converted into a digital number. Simulation:

Understanding Exposure & Shutter Exposure determines how light or dark an image is. The shutter opens to begin an exposure closes to end an exposure. the shutter speed setting determines how long the shutter opens to expose the image sensor. Try these simulations:

Resources Digital camera basics: How digital camera works: Copyright for Educators