The following is still based on discussion from the old manual. New data has been obtained, but has not yet been fully reduced into a format for inclusion into the present document. Performance, however, is comparable to that when Hydra was in use on the Mayall telescope.
Flux counts with the blue fiber cable.
The dropoff on the blue end is dominated by atmospheric extinction and the rapidly declining quantum efficiency of the CCD detector. The grating blaze function and color of the star are the predominant terms defining the slope on the red end of the spectrum. Estimates of exposure time can be extrapolated from Figure 9 by scaling the grating dispersion and blaze efficiencies, CCD QE, fiber throughput, filter transmission, and object magnitudes.