I'm still trying to maximize the autofocus-routine in Ekos.
I use a robofocus with a VMC200 telescope. The correct focus is around 9730 ticks, but it varies.
I have the options on: "auto select star", "sub frame", "dark frame", "max travel: 10000", "step: 50 ticks", "tolerance: 1%", "exposure: 1s".
Then I start the autofocus. He moves the focus a bit, up and down, but he never reaches the real optimal focus.
A V-curve is not really created. I just see some dots in a spread. Manually I have a best HVR around 1.2, but the routine never reaches that (best 1.8.). Result, my stars are slightly out of focus. When I follow the process in the fits-viewer then the star is every time a small donut, it never reaches the point of 1 lightdot. It seems to jump randomly from bigger donut to smaller donut, then again to bigger donut, mixed with other sizes of donut.
So, to optimize my parameters, I'm trying to understand what the routine does to calculate the optimal focus. What does the "tolerance" mean exactly? How does the routine builds the curve? If you select a high setting for the steps, say 100 or 200 ticks, how are you sure that the routine will return back to the good focus? Is it better to do larger exposure to be able to select a star in a star-poor field? Smaller exposures? At what point will the routine decide to try smaller step-sizes?
I use a robofocus with a VMC200 telescope. The correct focus is around 9730 ticks, but it varies.
I have the options on: "auto select star", "sub frame", "dark frame", "max travel: 10000", "step: 50 ticks", "tolerance: 1%", "exposure: 1s".
Then I start the autofocus. He moves the focus a bit, up and down, but he never reaches the real optimal focus.
A V-curve is not really created. I just see some dots in a spread. Manually I have a best HVR around 1.2, but the routine never reaches that (best 1.8.). Result, my stars are slightly out of focus. When I follow the process in the fits-viewer then the star is every time a small donut, it never reaches the point of 1 lightdot. It seems to jump randomly from bigger donut to smaller donut, then again to bigger donut, mixed with other sizes of donut.
So, to optimize my parameters, I'm trying to understand what the routine does to calculate the optimal focus. What does the "tolerance" mean exactly? How does the routine builds the curve? If you select a high setting for the steps, say 100 or 200 ticks, how are you sure that the routine will return back to the good focus? Is it better to do larger exposure to be able to select a star in a star-poor field? Smaller exposures? At what point will the routine decide to try smaller step-sizes?