Detector characteristics are given in this section. Note that the GMOS-North and GMOS-South detectors have different spectral responses, with GMOS-N having more red-sensitive CCDs and GMOS-S more blue-sensitive CCDs. Note also that the telescope optics are now silver-coated, reducing the system throughput in the blue.

The recommended detector read-out configuration for all GMOS observations is

• slow read
• low gain
• 3 amplifiers

The three best amplifiers are used, giving the lowest read-noise. It is recommended not to use the 6 amplifier mode or fast read, unless read-out speed is essential for the science goals of the program, i.e. time resolved observations. High gain is recommended only for programs that target very bright objects.