ASI120MC guiding

[kosborn]

Don't use an ASI120MC for guiding! If you do, this is what happens when you leave the telescope to make a cup of tea!

Kevin

[RickS]

Looks pretty ugly but how did a cup of tea cause this? ;)

[lazjen]

He only made one for himself. :)

[kosborn]

The camera loses sync every few minutes so PHD2 tries to guide on a star that isn't there any more. If I don't jump on it as soon as PHD loses the star this is what happens (sometimes though a cup of tea is more important than a lost sub :)).

Kevin

[kosborn]

Gabriela is back in frame and the tea is good!

[speach]

I have no trouble at all with my ASI120MC don't really understand why your loses sync

[Imme]

First bump in graph looks like you bumped it when you stood up, second one the vibration of you putting the tea cup down, third you biscuit :rofl:

I have the same camera and it will go all night on phd without an issue. You sure the problem isn’t caused from elsewhere? Remember the camera just the ‘reporter’ of something happening.....it may only be recording the issue.

Edit.....just had another look at the graph. The first issues goes north, the second 2 go south. I’d expect if it was a dropped frame or something similar that the constant of the earths rotation would show all issues in the same direction. I think you have other issues (but I’ve been wrong before!)

[kosborn]

If I sit and watch it (instead of making tea) I see the guide star shift horizontally to the left of frame in PHD. It doesn't matter what the orientation of the telescope is, it always shifts horizontally to the left (at the same y pixel value). Usually PHD flashes red, beeps and reports lost star and stops guiding although sometimes it seems to try to guide on something spurious until the camera gets back in sync and the guide star goes back to its proper position. If I stop PHD looping as soon as it loses the star and then immediately start looping again, the guide star returns to its normal position and I can continue guiding, usually without any blur in the sub. I must admit, I don't usually get crazy correction attempts like the one I posted but I usually catch it early.

You are lucky if yours is working well. Are you using Windows7 or a Mac? https://www.cloudynights.com/topic/572184-the-sad-state-of-the-zwo-asi120mm-and-asi120mc/

Kevin

[Bart]

I have seen this before and very recently as well.

I suggest that it may be tight spots in your worm wheel and worm shaft. If you give the drive mechanism a slight bit more clearance it might go away. Has the mount had a strip, clean and re-grease? It may have small amounts of debris in the mesh.

[kosborn]

I bought the mount new in February (I assume it was new although I subsequently bought filters from the same place and two of them had already been opened and presumably used). Do the worm wheel and worm shaft issues apply to the EQ6-R Pro which has a belt drive?

[Imme]

I’m on windows 10.

Definitely sounds like a mechanical issue to me, not camera

[speach]

"I see the guide star shift horizontally to the left of frame in PHD. It doesn't matter what the orientation of the telescope is, it always shifts horizontally to the left (at the same y pixel value)."
Rotate the camera through 90 deg and see what the graph is like then, If it still moves in the same way it's your mount not the camera.

[luka]

It is the camera. This is a known problem with the USB2.0 version of the ASI120 (the USB3.0 version works fine). Just google "ASI120 split frames" if you want to read more.

The issue happens mainly in conjunction with Windows 10 and then not on all computers. That's why the camera works for some people but not everybody.

In PHD2 you can try using the Directshow or ASCOM drivers, this has solved the problem for some but not everybody.

I had the same issues and eventually got a new guidecam. The ASI120MC is now being used for planetary.

The sad thing is that the camera is still for sale although the problem has been know for years :mad2:

[Bart]

Very interesting Luka, thank you for the info.

[benklerk]

I have the same issue as luka. I suffer from split frames. I also ordered a new guide camera. The ASI 174mm mini, still waiting for it to come by post from bintel.
The ASI 120mm will now become my all sky camera. But will see how it goes.