"Guiding on comet directly is supported by phd2, but it's tricky and manual"

from CdC you can send the comet guiding parameters directly to Phd2

Paul

Thanks!
Will try tonight using your suggestions.

Oh... I was completely unaware of the "Edit Comet Mode" in DSS. Now I am.
That's something I was missing (I was wrongly assuming that DSS would auto-detect a comet)

If you had a big enough guidescope, could you guide directly on the comet with KStars?

The processing program Siril can also deal with stacking frames containing a comet, though it helps to already be familiar with Siril as it has a bit of a learning curve (helps if you can read French, too).

I don't even see the comet on my guide camera...
Well. Shooting it right now. C/2019 Y4 ATLAS.
AT72ED with ATI294MC. 120 sec exposure, Gain 200. Guiding on stars. Internal guider.
The comet looks pretty small with my setup.

Agreed. KStars/Ekos doesn't have that feature. However, once the rates are sent, it still requires the mount to have good polar alignment and low periodic error. So that makes use of tricky prerequisites.

PHD2 also has a "comet training mode", which requires those guiding parameters, and around ten minutes of manual guiding to refine those for your own setup.

Note that none of this is "guiding on the comet" unfortunately. That's already quite cool!

-Eric

You're supposed to look for the coma it is expected to be around 12-15 arcmin currently, which your telescope can certainly handle. Leave the core for higher focal lengths.

-Eric

It's certainly visible. I am on the 40th frame right now..
The comet is close to a bright street light unfortunately. Getting terrible flares. I have limited viewing angles in my front yard : (

Is there any other software other than DSS and Siri to stack comet sequences? PI, I guess... (but I am not getting there).
I am still to try Siril.
DSS sort of works.
In 'comet only" mode it produces some strange artifacts.
In "comet and stars" mode the result looks better at first look but the background looks weird and the color is missing...
Maybe all this is just because my dataset is not very good.

Keep trying, it should work. My version of DSS can't handle the mode putting both comet and stars stacked, but the two others are working for me.

PI is not easy at all with comets (my own experience). However, you can batch-process your subs for noise and contrast and create a time-lapse, which is equally cool.

-Eric

I am not touching PI even with a ten-feet pole..
I did give Siril a try thought. It produced better results than DSS (for "freezing" the comet).
I think I am OK with comets now.
What I need is darker skies...
Thanks!

Here's what I've got.
Comet C/2019 Y4 ATLAS. Double montage. Stars "frozen" + comet "frozen" + the Moon to show the scale.
30x240s. ASI294MC Pro. Gain 200. -5C. LPro filter. AT72EDII scope. Bortle 9 with street lights all around.
Acquired with KStas/Ekos, Stellarmate 1.5.1 on RPI4. Stacked with Siril (worked better than DSS), processed in APP (to stretch and remove light pollution) and Photoshop.