DSI Dark Slide Install

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Had a late start to the night; I didn't start collecting data on M17 until 1:03 AM.

I had FocusMax issues; trying to figure out focus start positions on the FM setup tab. The critical focus position value seems to have increased. This may be related to ambient temperature which expands the OTA and "pushes" the focal point out the back of the OTA.  I began a log of date, air temp., RoboFocus focus temp. (value), and focuser position.

While data was being collected I recalled the use of the old Criterion manual shutter slide that was used in their off-axis guider system. I had cannibalized the shutter for a cold camera I had built in c.1982.  I found the cold camera and shutter in a box of photography supplies.  The shutter has T-threads which can be inserted in the off-axis optical path, in between the Meade Basic Camera Adapter (#07356) and the DSI CCD.  Now I just have to insert and withdraw the slide to take a DSI dark frame, rather than cover the OTA with the telescope cover.

I cut a piece of black construction paper 53 mm x 120 mm to act as a "shutter" for the Criterion manual shutter slide. The shutter slide has T-threads so that it can be inserted in the off-axis optical path, in between the Meade Basic Camera Adapter (#07356) and the DSI CCD.  Now I just have to insert and withdraw the slide to take a DSI dark frame, rather than cover the OTA with the telescope cover.  Works great.  Really need to make a dark library for the DSI and have guider images autocalibrated.