Thursday, March 23, 2017

Polemaster--Better than advertised!

It's been a week of disruptions and minor mayhem here, with clear nights that have been out of sync with my ability to take advantage of them. Until last night, that is.

My new Polemaster polar alignment tool worked quickly to give me a good polar alignment (as yet unconfirmed photographically). This was my first time trying it and I doubt if it took more than ten minutes to go through the basic and precise alignments. Some comments:
  • You initially need Polaris in the field of view. All I did is level the mount, set the altitude for my latitude, and get it eye-aligned with north. No bending down or stooping to sight through the polar axis. This brought Polaris into the field, although near the bottom.  I adjusted altitude and azimuth further to roughly center Polaris before beginning the alignment process.
  • Don't be put off by the coma you see around stars that are away from the center of the field of view. This isn't an imaging device for making pretty pictures; think of it more as a star detector. The coma shouldn't enter into the centroid calculations in a way that matters to the result, anyway.
  • Under the glow of my inner red-zone sky the device had no trouble finding the needed stars; The field looked best with the gain set to maximum. 
  • Several times you are asked to use the software to rotate the field of view. The rotation steps are a little coarse, making it difficult to exactly center stars in the target display circles. I don't think this matters much at all; all you need to do is get it reasonably close to the center.
  • At one point you use your hand control to rotate the field of view and see that a star stays on a displayed circle. If it goes off the circle you have to start over, but with modest care when specifying stars (using double clicks) the star will stay right on the circle.
  • Unless the manual has been rewritten, ignore it for the actual process of aligning. Instead follow the on-screen guidance--it's clear and perfect.
  • The USB cable is kind of short, but not so short as to cause a problem. Next time I use it I'll try adding a short USB extension cable.
  • When I was done the precise alignment indicator (showing a tiny box and circle whose centers will coincide when alignment is perfect) suggested that I was within atmospheric limits of perfect. Simply touching my mount would lead to a shift away from perfect.  This makes me wonder if the process is best performed when the mount is already loaded for imaging.
In summary, the Polemaster alignment procedure was smoother and simpler than I expected. Although I don't yet have tracking data or an image to confirm the quality of the polar alignment, I'm confident it was at least as good as most of my manual efforts using PHD or visual drift. And it was much faster and easier!





No comments:

Post a Comment