×

INDI Library v2.0.6 is Released (02 Feb 2024)

Bi-monthly release with minor bug fixes and improvements

Poor focusing results with lacerta MFoc

  • Posts: 321
  • Thank you received: 19
Learning how to use my new Lacerta Mfoc-System. This time no problems with getting it to run. It worked from the first day on.
But i am not sure about my settings in the focusing module.

the system works and tells me that focusing was succesful in eather 3 or 4 or whatever iterations. But it is just NOT in focus.
So i am trying around some time with different settings.

I thin i am right that in the beginning i have to set it ALMOST in focus postition manually, to give the system a chance to find a star by its own, right?
OK, after done so i set the maximum steps to 500, tolerance 0,1 step size 100.
System works and ends somewhere, telling me its in fokus, but its naturally not, just NEARER than before.
The i reduce the maximum steps and the step size down a bit like to 50 and 10 steps.
This causes the system to work in a smaller "path"
I did this yesterday until maximum working distance of 50 steps an da step size from one.

After that i hit AF. The system starts to move in a bit, out a bit, like it should, and told me its in focus.
So i started a testrun on m34, whole night by scheduler including refocusing after 60minutes.

I did not check the focus on a debayered picture because its full moon anyway, its only testing...

But too bad, like i was afraid of, the system was far from focus...

So has somebody an idea? Another setting maybe? anything?

You can see the defocusing easy by looking on the spikes on this screenshots from the center. This is a debayered singleframe made with my Moravian G2-8300 color.

cheers, Niki
Skywatcher EQ6-R | Lacerta 10" Carbon-Newton | Lacerta MFoc Motorfocus | Moravian G2 8300 Color | Canon EOS 5DMarkIIIa | Lodestar X2 guiding cam | KSTARS 3.4.3. on my outdoor-Laptop with KDE-Neon/Plasma | KSTARS 3.4.3. on Remote-IMac with Catalina | KSTARS 3.4.3 on Remote-Macbook Air with Catalina
4 years 6 months ago #43311
Attachments:

Please Log in or Create an account to join the conversation.

  • Posts: 1009
  • Thank you received: 133
It depends an many things of your focuser. Try going to looping mode, change the focus manually, then find out how much you need to move the focus to change the HFD value some 20%.
I'm not sure about max travel, whether this is the max move for a single movement, or the total movement. I've never touched it (AFAIR), it's still at 1000.
The other thing to check is backlash. If your focuser has (uncorrected) backlash AF cannot succeed. So you need to figure this out manually, moving through focus without changing direction, finding the best point, then revert direction and do the same again. Difference of the two focus values is your backlash.
Enter it in the driver (if it supports this). If not, you're probably out of luck :(

Would be nice if there was a subtab in focus for determining backlash.
4 years 6 months ago #43324

Please Log in or Create an account to join the conversation.

  • Posts: 321
  • Thank you received: 19
Tried around with settings yesterday, but i have to say something at first.

When i start up the system from scratch, connect my stuff and go to the focusing tab, i am NOT ABLE to make any settings.

I FIRST have to start autofocus, and AFTER THAT, i am able to make settings like max-travel, stepsize and so on.

The funny thing is, the parameters BEFORE i start are 0 for maxtravel and also 0 for stepsize.

Besides that, i managed to get some useful settings yesterday. They were MaxTravel 1000, stepsize 10, tolerance 1% and polynomial.

I let the system do a autofocus that took some iterations and was succesful in the end. then i checked the fokus with my bahtinovmask in the 10xmagnification in the lifeview of my DSLR, and it was perfect.

I´ll have some tries with this settings the next time its clear outside.

What i tried too was the settletime. i think this is for the focuser, so it has enough time to take the distance, BEFORE the next picture is taken? I believe this would be useful in my case, especially when there are quite BIG steps done like 50 or more.
I recognized yesterday, that the cam was taking the next picture, but the focuser was still moving...

Can someone check if the settle-function is working proper?


cheers
Niki
Skywatcher EQ6-R | Lacerta 10" Carbon-Newton | Lacerta MFoc Motorfocus | Moravian G2 8300 Color | Canon EOS 5DMarkIIIa | Lodestar X2 guiding cam | KSTARS 3.4.3. on my outdoor-Laptop with KDE-Neon/Plasma | KSTARS 3.4.3. on Remote-IMac with Catalina | KSTARS 3.4.3 on Remote-Macbook Air with Catalina
4 years 5 months ago #44124

Please Log in or Create an account to join the conversation.

  • Posts: 1009
  • Thank you received: 133

Uh, that sounds strange. So you cannot even use the single-frame button to only start a single exposure?

I have no real idea what is wrong there, but after some own experience¹ I would suggest you backup/move away your config and start with a 'virgin' setup to check if this persists.

¹ I had updated my kstars from an older version, keeping the config files. Then I tried to activate HiPS overlay. I could select catalogs to use, but they wouldn't show up as selectable, and next time I opened the settings they were gone again. Clean restart, and it just worked....
4 years 5 months ago #44128

Please Log in or Create an account to join the conversation.

Time to create page: 0.602 seconds