The above diagram shows the chromatic performance
of the 4" custom coma corrector from 400nm to 700nm (top
row) and from on-axis (0.00mm) to off-axis (26.0mm). The corrector
shows the largest stars at 400nm, but this occurs mainly at the
extreme off-axis location (26mm). Since our atmosphere absorbs
most UV rays and CCD chips are often very low in QE at 400nm,
this is of little concern. The white square boxes are 25 microns
on a side, so this again is completely acceptable because we
are well within the 25 micron area. |
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