Level 2 Help for TRISTIM

ILLUMINANT: specifies the illuminant by whose spectral radiance the C.I.E.
color matching functions are weighted.
 
Valid values are: D55, D65, D75, A, B, C, XENON, CMF.
 
The first six of these (D55 thru C) are C.I.E. standard illuminants.
Note that D55, D65, and D75 refer to blackbody curves (Planck function)
at 5500, 6500, and 7500 Kelvins, respectively.

XENON specifies that the illuminant is the JPL 12-inch light cannon No. 1.
 
CMF specifies that the unweighted C.I.E. color matching functions are to be
used.

RADIANCE:  List of numbers which specify the spectral radiance or reflectivity
or transmittivity of the object under study.  
 
This spectrum must be specified at exactly 40 points, starting at 380 nm 
and ending at 770 nm.  Up to 10 separate spectra may be specified, each of
40 points, which will be multiplied together inside the program to obtain
the final spectral distribution.  These separate spectra are simple entered
sequentially under this parameter.  E.g., if RADIANCE contains 80 numbers,
of which the first 40 are 2.0 and the next 40 are 5.0, then the resulting
spectrum values are 10.0 at all 40 points.
 
Note that the user may also cause a linear transformation to be applied to
the input spectrum, using the ADD and MULT parameters.

ADD: This is a constant that will be added to each of the 40 spectral 
values specified by the RADIANCE parameter, before computing the tristimulus
values.

MULT: This is a constant that will be multiplied with each of the 40 spectral 
values specified by the RADIANCE parameter, before computing the tristimulus
values.

This specifies 40 points that will be used as a reference (continuum) spectrum
to compute relative radiance values from the values input in RADIANCE.

If this parameter is defaulted, then no relative radiance computation will
be done.

This specifies 40 points that will be used a background spectrum if the
parameter CONTIN has been specified (if not, then this parameter is
ignored).

If only one value is specified, then that value will be used for all 40
points.