The following are values scaled off chart records of scans across the
wavelength range of most of the filters in the Polar Camera filter
wheels.  The scans were made with the ISAS 1-m monochromator, in first
order, with short-wavelength blocking provided by an Optics ______ 500
nm long-pass filter.  The entrance and exit slits were 0.050 mm wide,
and the incident light was provided by the ISAS pinhole source,
collimated by a 147-mm focal length lens, and converged into an f/4.6
beam with a 146-mm achromat preceded by an iris which limited the beam
diameter incident on the achromat to 31.7 mm (or so).  The convergent
beam was focused on the entrance slit.  

The "aim" of the pinhole source was optimized by mounting the front leg
in a vernier stand which allowed the leg to be adjusted in the
horizontal direction perpendicular to the optical bench rail. The
vernier was adjusted until the output voltage from the PMT was a
maximum. The output of the pinhole source was stabilized by powering the
lamp supply from a small Sola constant voltage transformer. This was
found to produce a significant improvement over powering the lamp supply
directly from the AC mains.

The filter wheel holding the filter under test was clamped to a jig
mounted directly on a "holder" compatible with the optical bench. The
clamping was done with a toolmaker's clamp belonging to R T Miller. The
front surface of the filter deviated by one or two tenths of a degree
from perpendicularity to the chief ray of the beam, but this was judged
to be insignificant compared with the six-degree inclination of the rays
at the edge of the incident beam.

All measurements were made on August 14 and 15, 1996, by D P Steele.

Cam Filt      Peak      Wavelength    Center         Half       FWHM
          Transmission              Wavelength   Transmission
=== ====  ============  ==========  ==========  ==============  ====
 0    0      0.494        8289.0      8292.3    8275.1  8309.4  34.4
 0    1      0.461        6088.4      6085.9    6064.8  6106.9  42.1
 0    2      0.335        6305.3      6304.1    6299.4  6308.7   9.2
 0    3      0.444        6667.6      6676.8    6653.9  6699.7  45.8

 1    0      0.487        8346.7      8348.4    8335.0  8361.7  26.7
 1    1      0.500        8225.0      8210.0    8169.0  8250.9  81.9
 1    2      0.481        7853.7      7853.2    7827.3  7879.1  51.8
 1    3      0.411        5580.7      5581.7    5576.1  5587.3  11.2