MoonLite NightCrawler and SGP -- Feedback

Probably preaching to the choir here, but I just installed a MoonLite NiteCrawler on my FSQ106, and used the rotation feature at the onset of a sequence. The rotation happened, but it took 20 attempts to get both the centering and rotation to agree, and it should have taken far less, based on the images I saw on my screen.

I get that this tech is fairly new – so no harm, no foul, but I would strongly advise that this logic be improved.


I find the rotating and centering logic in SGP to be excellent, so I suspect you have problems outside of SGP. I use the Optec rotating-focuser with my “angle” error set to 1 degree and centering set to 10 pixels and 5 attempts. 99% of the time, I am centered and “rotated” with two tries.


It could certainly be configuration, as I just set it up last night. Focusing was fantastic, rotation was the challenge. I will dig into the configuration some more and see if I can get it working better. Two runs for centered and rotated would be awesome.

I plugged in the settings you suggested and will give this a go tonight to see if it improves.

Do you sync the rotator to the sky in some way prior to a sequence running?

You may want to verify that the rotation is actually rotating the correct direction. For instance when rotating from 0-30 the rotator should rotate clockwise when viewed from behind. If I recall correctly I needed to reverse the direction of rotation in the ASCOM driver (or someplace) to correct this.

I’ll try to pull it out this evening and verify that. I owe Ron some screenshots anyways. Beyond that we’d need logs to see what’s going on.


Thanks Jared,

It does seem to move in the right direction. I am going to try the sync and solve method of getting the rotator synced to the sky and see if the situation improves.

Just waiting for the camera to cool and will know here in a few.

Big improvement. Took 2 runs to get both the rotation correct and the centering completed. I’ll be sure to sync and solve from now on at the start of my sequences!

Problem solved :smiley:

Spoke too soon, looks like my test was already rotated how it needed to be, so nothing happened.

When I went into Framing and Mosaic Wizard and created a sequence with a rotated image, I ran into the problem where the rotation of the image was always off even after it was moving to try and get the rotation correct.

I tested the direction of the rotator by setting it to 0, then in SGP asking it to move from 0-30. It moved, and moved clockwise. Should it be counter clockwise instead? The reverse checkbox was not checked.

Attached the log (318.6 KB)

You will probably want to skip to here in order to see and avoid a bunch of noise:
[09/02/17 23:35:44.323][DEBUG] [Sequence Thread] ********** Run sequence started **********

The struggle with centering and rotating is pretty clear in the log after this section. (59.9 KB)

Another night, another log. Same issue.

Looking at the second log I can see that the rotator and camera are rotating by the same angle but in opposite directions. I put the positions such as “Sync complete. Camera angle is 164.11; Reported pos rotator position: 294.10” into a spreadsheet and it’s clear that this is what’s happening.

Would it be worth having a rotator calibration wizard in SGP? If would collect and solve an image, rotate by a reasonable amount. maybe 60 degrees, then collect and solve another image. The angle change should be the same and the difference in the direction of rotation can be used to set the rotation direction flag.

Yeah that was my experience while watching the rotator in action while the sequence was running. I will likely just move the rotator manually to get the object framed up how I want it, but being able to do this automagically would be great.

As far as the workflow I used, here is how I have been using the NiteCrawler:

  • Connect camera, focuser, and rotator in SGP using the correct (default) profile for my FSQ106 at its Native focal length.
  • Confirm that image scale (1.43"/px), telescope focal length (530mm), and other desired settings are correct.
  • Get in good focus using the control panel buttons, then run the auto focus routine (twice).
  • Use the Sync and Solve feature to allow SGP to know the current camera angle.
  • Use Framing and Mosaic Wizard to frame/rotate a target how I want it.
  • Create Sequence, populate exposure details, start sequence

Why not just reverse the rotator direction? There are two places you can do that, in the driver or in SGP. Don’t do it in both.

Will that solve the problem? If so, I am more than happy to test it.

Tested, confirmed the issue is now completely solved.

Thanks Chris.

I was having the same issues as Bill. I tried reversing the direction in the ASCOM driver but it wasn’t working correctly.

I had to reverse the rotation direction in the SGP settings then all was well


1 Like