The major advantage of CCDs over other detectors is their high efficiency. The wavelength response for the types of CCD currently in use on La Palma is shown in Figure . The best (thinned) devices have a peak efficiency of about 80 per cent, whilst the unthinned ones have a peak efficiency of about 50 per cent.
[ TIFF ]
Figure: Responsive Quantum Efficiency (RQE) as a function of wavelength for the Tektronix and EEV CCD detectors most commonly used on the La Palma Telescopes