How cameras work

Editor's Notes

• #3: What you see is what the lens sees. The mirror is hinged to move out of the way when the shutter is opened.
• #4: Note how the mirror moves upward to expose the sensor.
• #5: You look through the viewfinder and see a slightly different view than the lens.
• #6: (Walk through the process again and end with looking at the shutter and sensor.)
• #9: These are found in the lens itself. The individual leaves must cycle open and closed, so it takes a bit longer to cycle through an exposure. This is the type shutter found in compact cameras.
• #10: This type of shutter is usually made of two curtains that follow each other across the sensor. This shutter is found in the body, not the lens of SLR’s.
• #11: First the array of light-sensitive sensors turns the image into a mosaic of picture elements, or pixels, with luminance (brightness) and chrominance (color) information. Next the photosensors produce a single stream of electrical signals that are converted by integrated circuitry into digital data. The digital data is next taken apart by powerful computer chips and software to extract the color and brightness data in order to construct the final image. Last the circuitry sends the image data to the electronic memory card. Some cameras use a temporary storage which speeds up the picture taking operation.