The model 77782 is the RS-232 / USB version of the MS257™ 1/4 m Imaging Spectrograph. The MS257 spectrograph is a completely automated, efficient 1/4 m instrument, with enough versatility to satisfy most spectroscopy applications. It is an F/3.9 instrument with a focal length of 257.4 mm, usable as a monochromator or true flat field imaging spectrograph. Stray light is negligible, and there is no re-entrant spectra. The MS-257 has 2 output ports, 1 input port (with optional accessory can support 2 inputs), and supports 4 gratings.