FYI - new synscan version 3.35

[toc (Tim)]

http://www.skywatcher.com/swtinc/cus...1=1&class2=101

SynScan(TM) Hand Control Firmware (Ver.03.35) Release Note
Date: Apr. 24, 2013
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1) Implemented an all new polar alignment algorithm. The Latitude adjustment and Azimuth adjustment have been split into two steps.
2) New adjustment allow users to set the maximum altitude for a GoTo slewing on equatorial mount.
3) Some bugs were fixed, including: PAE inaccuracy in some regions of the sky, frozen of directional buttons after starting from parked position, and incorrect tracking speed after GoTo at the Moon.
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[pluto (Hugh)]

I tried out this new firmware the other night. Mainly I was looking at the polar align feature.

First I set up and did a 2 star align, all looked good.
Then I did the polar align first on Sirius. It framed fairly well straight up so I figured the 2 star align had worked ok. I went through the alt and az adjustments. The reported error was quite small but I thought I'd repeat and get it closer.
So I did the polar align on A Cen and the reported error was zero!

I was feeling very pleased at this point so the cloud gods decided to punish me.

The clouds suddenly appeared so I though I'd leave it and come back. Unfortunately I bumped the power plug and the hand controller switched off. "No problem" I thought as the mount is aligned and I can just move the mount back to the park position and do a new 2 star aign.

The clouds finally cleared so I powered up and did a 2 star align. That went fine so I thought I'd re-run the polar align just to refine it a bit. This time the polar alignment was way off, like 7 degrees or so in alt and a degree out in az!

At this point I decided to drift align and not waste any more time. After drift aligning it became apparent that the actual alignment was closer to where it had wanted me to set it the second time (ie. 7/1 deg different from the first alignment).

Perhaps there was something weird going on with the first alignment, I'll have another go sometime but for now I'm going back to drift aligning.

Has anyone else had a go at polar aligning with the new firmware?

[Steffen]

I find the polar alignment procedure a bit peculiar (compared to the 3.28 procedure), especially the bit where it tells you to adjust the azimuth screws to bring the star as close as possible to where it ended up during the previous alt alignment step (you have to memorise that position in your reticle). Be sure to read the updated 3.35 manual.

Version 3.35 doesn't appear to have the glaring bug where it would double the polar alignment error with every alignment step rather than reducing it. I have gotten to sub-30-minute alignment errors and didn't go any further (I don't do imaging). There is still the occasional odd result with 3-star alignments, where the alignment was declared successful yet goto accuracy was not good enough to put the target in the field of view at 150x. Other times it works well and goto is reliable at 240x. It seems the alignment algorithm still isn't as robust as it should be and depends much on the set of alignment stars on offer.

Looking forward to further refinement

Cheers
Steffen.