CCD Cameras
Inside a CCD camera
Credit: ING, La Palma
They are used on most modern telescopes both because they are so sensitive and because they produce digital images.
These digital images can then be transferred easily around the world using the Internet and processed using special astronomical data reduction software.
This is much easier, quicker and more accurate than "scanning in" photographic plates.
The electronic chips inside CCD cameras are very much like those in video cameras and small digital cameras. However, to make them very sensitive, they have to be kept very cold - usually below -100°C!
CCD cameras only measure the brightness of an object, not its colour, so special coloured filters are used to make simple measurements of the colours.
