next up previous contents
Next: Fringing Up: General features of the Previous: Correcting frames that were

Electronic ghosts

For bright sources, one can see electronic ghosts which are 8, 16, 24, etc. rows away from the true source. The amplitude of these ghosts depends on the brightness of the source, their position relative to the central row and how fast the array is read. The faster the array is read, the stronger these ghosts are. For very bright sources, one may see a negative ghost which is four pixels away from the source. Prior to March 2001, the array was read out more quickly than it is now, so these ghosts were significantly stronger.

Christopher Lidman