Specifications

AUTOSTAR CCD PHOTOMETRY 35
The set of standard RGB astro imaging filters is provided at extra
charge. The advantages of using the DSI Pro with the external
filters are that the monochrome camera is more sensitive, and
provides better resolution, as well as allowing use of different
filters.
While the included filter slide could be used to hold photometric
filters, it quickly becomes apparent that is not a good idea. The
specialized BVRI photometric filters are expensive, and the filter
slide is of open construction, exposing the filters to dust, dew,
fingerprints, and scratches. A filter wheel (turret) is a much better
way to hold and protect the filters.
Adding a Filter Wheel – Installing the Nose Piece
Adapter
The first step in readying the DSI Pro for photometry is to replace
the stock filter slide holder with a low-profile adapter plate similar
to that used on the color DSI (see Figure A-2). This gets rid of the
large openings where the slide goes and also reduces the distance
from the filters to the CCD chip. The adapter is threaded for
standard TEE thread accessories. In the U.S. this adapter plate can
be purchased for about $40 from ScopeStuff. (See the list of
suppliers at the end of this Appendix.)
Note: The original standard TEE threaded to 1.25 inch (31.7 mm)
nose piece can also be used with the new adapter, but it's better to
mount the filter wheel closer to the camera than allowed by the
nose piece. The filter wheel we describe comes with TEE thread
couplers for the purpose.
Replacing the original filter slide holder adapter with the low-
profile adapter plate is very simple. There are four small Phillips-
head screws that hold the adapter in place. Those screws and the
original adapter are removed and replaced with the low-profile
adapter using new shorter screws (provided).