Hello,
When building optical trains, int he guiding menu, I can chose between none, the camera or the mount, which seems normal since there is no extra device declared for this purpose.
However, I am still wondering what the best choice would be.
What would happen upon setting each of the proposed choices ?
Rgrds,
J.-Luc

I use an off axis guider and in my optical train for guiding I have Camera set to my guide camera and Guide Via set to my mount. I don't have an ST-4 cable connecting the guide camera directly to the mount and instead I let EKOS handle the guide pulses to the mount. Over the years I've read a number of recommendations favoring pulse guiding from the computer rather than using the connection from the guide camera to the mount. I'm sure there are a variety of opinions on that.

Best,
Fred

Hello Fred,
So, the way it was in my case was a non-sense, and the cause of drift in tracking, am I right ?

Jean-Luc - that's a loaded question! On the limited topic of optical trains, I have an optical train for guiding set up as I described and that's the train I select in the guide module and it works really well. In the other EKOS modules (Capture, Focus, etc.) I have an optical train for imaging selected (which is the train that includes my primary imaging camera).

While I think this may have a positive impact on guiding (only your experience will tell), there are so many things that go into good and bad guiding I hesitate to declare that this was the cause of drift!

None = no guilding
Mount = guilding images are sent from the guide camera to the computer running the Guide module / PHD2. Guide / PHD2 works out pulses to move the mount to keep the guide star(s) in the correct position and sends from the computer directly to the mount. So there needs to be a connection from the computer running guiding to the mount. This is usually called pulse guiding.
Camera = guilding images are sent from the guide camera to the computer running the Guide module / PHD2. Guide / PHD2 works out pulses to move the mount to keep the guide star(s) in the correct position and sends from the computer back to the guide camera. The Guide camera sends the pulses to the mount so there needs to be a connection from the Guide camera to the mount. This is called ST4 guiding.

ST4 was the original way to do guiding. Pulse guiding is now the usual way as it involves 1 less connection (guide cam to mount) and 1 less hop for the guide pulses to have to make.

I modified the train so the guide device is set to "--".
It was previously set to "Mount".
Thanks to both.

The guide device should be set to Mount in the train you use in the Guider panel. If you set it to "--" (i.e. None) , then it won't be guiding. At least that is my understanding.

Bill - I agree with you. That's the set up I have - the mount is set as the guide device.

Well, then I feel lost.
I just have one imager and the mount. No extra device dedicated to guiding.
So, shouldn't I set guiding to none ?
Also, as I don't use extra guiding device, the train is the same in all tabs.
I'll check as soon as I can take photos again, but I think I had to do this way, otherwise it did not work at the time I set it up.
Then, I don't modify anything that works, until I face situations where it fails.

Don't you have a guide camera? You can't guide using the main camera while also using it for imaging.

I have two trains, one specifying the image camera. This is set as the one to use in the CCD tab. I also have a Guide train that specifies the guide camera as the Camera. It also specifies the mount as the "Guide via" device.

ETA: Re-reading your original post, it seems that you are not trying to guide, you are just taking unguided images. In this case you are correct that the "Guide via" setting should be set to "--".

That's fine, I wonder why I had set it to Mount once, probably a misclick while trying to adjust something else.
Thank-you for helping.

Jean-Luc, it sounds like you've got this sorted but I've attached screenshots of my set up for opticat trains and guiding just FYI. I think this is the similar to what Bill was describing.

Good luck!
Fred