
    The observing and output parameters are set in the SPTIME task
    parameters.  They may be modified at any time by typing "epar sptime".
    Parameters you might want to set are the exposure time (INDEF to
    compute the time for the desired S/N), source spectrum, source flux or
    magnitude, and graphics output.

    The output of SPTIME consists of text information at the central
    wavelength and optional graphs as a function of wavelength across the
    spectrum.  To select the graphics output set the "output" parameter as
    a list from the choices "counts", "snr", "object", "rate",
    "atmosphere", "detector", "emissivity", and "thruput".

