First Light - Starizona SCT Corrector III

 10/13/2024 -- Configuring the venerable Meade LX10 2000mm/F10 SCT with a new 2" visual back and the Starizona SCT Corrector III.  Set up spacers to ~1mm of the 83.8mm backfocus needed with the Svbony 405cc camera (based on a total required backfocus of 90.3mm for the SCT Corrector.  Skies were very poor with huge moon and clouds... but was anxious for first light to see how this new corrector performed.  The mount was nominally polar aligned from previous work (10/12) with the Celestron 10" newtonian attempting to fix collimation (only partially successful).  Reworked the counterweights and checked the balance of the LX10, spacers, RACI guider with Zwo ASI120MC-S and SCT corrector.  Then worked to achieve focus... which was ultimately successful (after cranking the focus to the left substantially).  Views of stars in the M31 area looked uniform and round across the whole field.  

Set up a job in the scheduler for the center of M31 with 80x40s light frames (repeating until 04:30) with the camera configured at 5c, with an offset of  32 and gain of 285.  Initial views in ASTAP looked reasonable with some vignetting visible in the corners.  Because the mount was not re-aligned (and likely due to wind gusts...which were present during the evening), guiding results varied from RMS of ~4" to 10 (very bad)....which was unhelpful.

Seeing forecast from cleardarkskies for 10/13-14 illustrating less than ideal conditions...just enough sky to do a basic first light test.

Seeing forecast from meteoblue for Silver Spring looked only slightly less dire than cleardarkskies...but marginal even for a basic test.

Collected 20x flat frames using the LCD light panel set to the lowest brightness with several sheets of construction paper to further dim the intensity to achieve a collection spanning 6 seconds while maintaining the same gain (285) and offset (32) settings used for the light frames. Collected 20x6s dark flats as well as 20x bias and 20x40s dark frames.
 
Analytical results page from AstroPixelProcessor for the 72 light frames integrated into the final rendering for the center of M31.
Processed with AstroPixelProcessor for the top 72 light frames of 76 collected.  Found a need to crop due to drift (likely from the drizzle step).



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