Hello,

I am using PHD2 for the guiding. My camera is an ASI ZWO 120 on a guide scope.
My EKOS profile is correctly set on PHD2 and the guide value is empty because managed by PHD2.
For the guiding control of the mount I use the ST4 port on the camera.
My problem is that each capture, the EKOS guide module indicates that the star is lost and resets guiding, although is not visible at PHD2, everything is fine.
I set the dithering value at 4 pixel but after 3 captures, the dithering is not fonctionnal. I tried without dithering and it's the same.
I have not yet tried with the internal guidance module

Any ideas ? INDI, PHD2 or camera driver?

Thanks for your help!

Hi,

Do you have an ASI120 (USB2) or ASI120-S (USB3) camera? The first is known to be problematic and if you have that then that could very well be the problem.


Clear skies, Wouter

I have a old version, USB2
I use the compatible driver ASI120MC-compaticle.iic

Even with the compatible firmware I never managed to make the camera work. Some people have reported success using 8-bit mode instead of 16-bit but that, too, never worked for me. So if 8-bit mode doesn't work for you then I am afraid you'll need to purchase another camera. I have been using the ASI120MC-S (USB3) cameras on various setups for several years now and they work flawlessly.


Clear skies, Wouter

My camera work normaly. The guiding is perfect.
But every capture with my Canon DSLR, Ekos Guide Module indicate star lost and initialized the guiding. On PHD2, I don't see the same

Are you using multi-sep guiding? This can protect against lost frames which can lead to unnecessary pulses that only compound the issue. I noticed the ASI120 frames can arrive late when the primary camera is downloading an image from a remote device as it saturates the server bandwidth.

OK, maybe very wild guess - could it be that the ST-4 guide pulses are interpreted as 'mount is slewing', and you have set the option to reset calibration after a slew (in Guide->Options)?

Hi,

Yesterday evening it was clear. I continued my tests.
PHD2 very often displays star lost mas star mass has changed. It lasts 1 second and it starts again
I see my camera quickly displays a wrong image (noise?)
Ekos resets guidance each time and it blocks the capture
I failed to guide with the internal tool. In automatic he never found a star. With manual choice of the star it could not be done either

"...and you have set the option to reset calibration after a slew (in Guide->Options)?"
Yes this option is enabled by default. I go try this night without

"Are you using multi-sep guiding? "
Yes, I try but the result is the same


I have doubts about my camera

I had seen those single bad/empty frames, too. For me they mainly (only?) happen if I use subframe readout in PHD2, so I'm using full frame. I had first thought it is collisions between the main camera and the guide camera when sitting on the same USB hub, but I think it's not. Nevertheless I run them on separate cables directly connected to the computer. (My cameras are a 1600MM-Pro main and a 290MMmini guide)
Also, I have disabled the star mass detection in PHD2 after several false alarms in the beginning. Might have been bad settings on my side, but as I'm not really plagued by clouds I don't depend on it anyhow, and left it disabled.

Thank you very much to everybody for your help.
This is an excellent way. I 'll go to plug my camera directely on my raspberry pi4 without trough the USB hub.
I will look at the full frame settings also

After my tests last night.
When capturing an image with my DSLR, the system has to slow down due to accessing the SD card of Raspberry Pi4.
This leads to a loss of the guide star and EKOS reset the guiding. I have restored my SD CARD with my old version of 15 days ago (Ubuntu 19.04 and Kstars v3.4.1)
I have the same problem, the star is lost about 1 second but Ekos did not reset the guiding. Ekos allways run the guiding and this does not turn off dithering on other captures.
In version 3.4.5, this causes reset the guiding
Sometimes on version 3.4.5, when the guide star is lost, the DSLR captures with short exposures although the ZWO camera is dedicated to guiding
This usually causes the program to crash
I ordered a SANDISK extreme PRO fast SD card a few days ago, originally it was to speed up my RAW recording times. Hope this will solve my problem as well