Testing, Testing, Testing here, because of moon.

i´d like all the KStars Users here to post there internal guider sessions, which work for them. Maybe we could get a trend for best guider settings this way.

I am trying atm lots of different settings. And the far best results are with the setting "fast" in the algorithm.

This causes a guiding-curve of most of the time under 0,5 Arcseconds! BUT: too bad... there are then peaks, about 1 per minute, with more then 2 arcsecs that kill the exposure.... Since they are not regular, i do not think it´s something to do with the Periodic failure...

This doesn't look like a software related problem to me. I'd double check whether the guide camera sits firmly connected to the scope and doesn't tilt. Also I'd check whether the guide scope is firmly mounted. Cables can move a camera over time so that might be something to look at, too. What strikes me is the symmetric pattern in the drift plot. I'm pretty sure this hints what the issue might be but I have no idea what it is. The guide star always "escapes" in a 90° angle.

Hi!

Checked the Cable 3 times, they do not affect the cam/Scope. All Screws are tightened very firm. I do not think the scope moves, neither the Cam. But i will check it one more time to be sure.
What do you mean with Symmetric pattern? Can you mark that for me, or explain please? Do you mean that both axes make the "jump" at the same time?

cheers
Niki

What I mean is this:



With one lone exception it's always a 90 degree angle and the distance from the center is the same, too. BTW, the lone exception looks like a combination of the two other positions next to it. This is not a coincidence.

With a x2 binned ASI120MM, 68.9'x44.2', that's a 6.4"/pixel resolution for guiding. Could you clarify what the resolution is for your imaging CCD? You may have mentioned that earlier but I'm not sure I understand how a drift of 2" could kill your exposure?
About the sudden drift, it's indeed interesting, it may mean a few of the exposures were taken with a sudden offset. That could be physical, agreed, but that could also be software-related, like a pixel offset or a split frame... We see that the guider tries to correct the drift, that the second frame is probably showing counter-drift, and then the star returns to center...
I remember having a similar issue with my DMK in the past. Frames would get offset by a few lines every now and then, making guiding impossible. I was about to drop the hardware, and somehow it resolved by itself, no idea how: cable, supply, noise, driver...
So I suggest taking a large number of day frames of a static environment with your guiding cam. Check whether all are aligned.

-Eric

I am not so firm with the sensor sizes compared with telescopes. What i have is s 1000mm newton telescope with a Moravian G2 8300 color.

I do not know how my exposures are affected, but they are...




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With a 1-meter focal length scope and your Moravian sensor, you get a resolution of 1.1"/pixel. You'll need a minimum of 1/6th pixel guiding accuracy on the guide scope to get the most of your sensor. You'd better unbin your guiding CCD!
By the way, did you try to expose for 4-5 seconds instead of 0.5? You need to trust your mount at some point. And if the problem is software-related, that will certainly help relaxing the connection.

-Eric

OK. So i switch binnig to 1X1 and make the exposuretime of the guidecam longer.
this will be my next try. Thanx

From my experience with guiding i would suggest installing the guide camera's and the mount's usb cable directly at your pc and not through a usb hub. I had a similar problem with phd that would spike my RA avery so often but not consistent and i once i lace the usb cables directly at my pc this issue has not bothered me

I am not using a hub, its all connected direct.


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