From: Milton Aupperle <milton@outcastsoft.com>

Date: July 8, 2012 11:24:17 AM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] Guiding on a Sunspot

Hi Bill;

The original design of the solar tracking code(developed back in 2005 if I remember right) was to do the calibration off a "feature", like an isolated inverted sun spot. After that it should work on tracking the un inverted limb reasonably well. I used to do this on an EQ2/3 mount with a hacked hand controller to test out the guiding code on a 1510 mm MAK 127 mm scope - letting it run for hours at a time. I haven't done any solar in a very long time and am just getting back to it.

However, one did need to have an isolated sunspot on the disk, set the camera to invert the image for calibration and it could not be near the sun edges. Once it had the sun edges in the field of view, it likely will not work reliably. If your using a short focal length scope and the whole disk, this likely won't work unless you can use hardware ROI on the cameras to isolate a sun spot.

We will need to take this off lists so I can get all the information I need. I will need to see:

1) Image showing what your trying to do the alignment with from the camera with and the capture log for the camera. This MUST be the same as what your doing the mount alignment with.

2) Your guide log that Astro IIDC recorded. That shows me all the Guide and Calibration settings you used and the response from the mount.

3) How good is your mount for polar alignment? I usually do it off a star, but a bright inverted sunspot at the center of the

4) How much slop does it have on the Dec / RA Axis - all CGE mount shave slop and that needs to be quantified and eliminated. We talk about how to recognize slop in the Guiding section.

5) What guide rate (for the Auto Guider port that the GPUSB connects to) did you set in the hand controller for your mount? My HEQ5 has a default value of 0.25x at startup. When shooting at 1.6 meter focal lengths, I usually bump that up to 0.75 x so it can make fast corrections. At shorter focal lengths, your going to need more than that to make the corrections quickly.

6) A general description of what your doing.

Send this all to me at my support address of "support@outcastsoft.com".

And generally speaking to everyone, if you have a problem it's best to send it directly to me at the support address as then we don't have the above requests scattered through the yahoo list.

HTH..

Milton Aupperle

On 8-Jul-12, at 7:10 AM, Bill Pearce wrote:

Sorry guys, I'm playing the stupid card. I can usually figure this stuff out, but I must be over complicating things.

It all works great except I cannot get this darn thing to guide. I've got the GPUSB cable, and it manually corrects the mount just fine using the software keypad. I'm using a CGEM mount and a Lunt 60 Ha Solar Scope with an Imaging Source DMK 31 AF03 monochrome CCD camera. I've tried to follow the instructions, but I seem to be missing something. (maybe PHD, and the SSAG spoiled me) As of now, I'm having to do sight corrections using RDP and my Ipad while doing other things inside. The Applescript works just fine, so does the movie conversions, etc. Great work Milton…..Brian was right. Now if I can just get over this guiding learning curve, I can pretty much fully automate my Solar imaging sessions.

Thanks in advance!

Bill Pearce

Mahoning Valley Astronomical Society