CCD

CCD cameras have been available to amateur astronomers since the late 80's with the introduction of the SBIG ST-4. CCD is the acronym of "Charge Coupled Device".

The way a CCD array transforms an image into a computer file is quite simple in principle. Light falling on a grid of detectors produces a pattern of electric charges, which are measured, converted to numbers, and stored in a computer.

CCD detectors have high quantum efficiency (they can record up to 60% of the photons that strike them, and even more in some systems) and exhibit a very good linearity. This means that images of deep-sky objects can be obtained in a few minutes and the output can be processed using standard image processing techniques.

All the deep sky images of G.AS.PR.A. association presented here were acquired with a Hi-SIS22 CCD camera.

This camera is an old model now !
New CCD camera have bigger and more sensitive sensors.