The two types of electronic detector available on La Palma are a range of Charge Coupled Devices (CCDs) and the Image Photon Counting System (CCD-IPCS). These are described in Sections and respectively. The CCD-IPCS is available only at the WHT, where it is an option on the UES, the blue arm of ISIS and on TAURUS. A strong case would have to be made for using the IPCS for a particular application, since low noise, thinned, Tektronix CCDs are available at all three telescopes. Section discusses how to decide which detector is best suited for a particular application.