Automatic meridian flip with autofocus

[AstroBernd]

Is it possible to force an autofocus (normal or full-frame) after a meridian flip, ideally before the "plate solve and center telescope command"? This is helpful to compensate for mirror and focus shift.

[Dunmunro]

Is it possible to force an autofocus (normal or full-frame) after a meridian flip, ideally before the "plate solve and center telescope command"? This is helpful to compensate for mirror and focus shift.

When I use my script I time each sequence of subs to end just after the mount passes the meridian.

example: I want to begin imaging at 8pm, and my target object passes the meridian at 10:42PM so the time from start to meridian is 162min. Each sequence begins with a plate solve, and centre and autoguider calibrate. each 5 minute sub is programed to do FF autofocus and with download time, each sub lasts 6:02, so 27 subs = ~163min plus ~4min for the slew, platesolve, centre, and initial FF autofocus. So the 2nd sequence will begin about 5 mins after the mount passed the meridian, and my mount is programed not to flip until 10mins after it passes the meridian, but the 2nd sequence goto will force the meridian flip.

Target1 - 8pm start - 27 subs
Target1A - 10:47 start 27 subs
Target 1B = additional 27 subs ( add more appended targets to the list until the desired number of subs is reached )

This is not the best way to do this, but it works for me, and I'll experiment with a better script when I head north for the summer.

[AstroBernd]

Hello Duncan,
Thanks for the quick reply. Yes, this is usually possible to time everything so the flip occurs only after one object is finished. But things may not always work out in this ideal manner.
Therefor my question.
Appreciate your answers
Bernd

[fabdev]

Hello,
via script it's possible, for example:

Code: Select all

side = "?"

' ....
' initialization
' .....

' before an exposure:
if Telescope.PierSide <> side then
   side = Telescope.PierSide
   Camera.FullFrameAutofocus(...)
   Telescope.AutoCenter(...) 
end if

however, since you cited the option "Plate solve and center telescope" of the Meridian Flip Monitor, maybe you intended an option there, not a script ?
By the way, a small defocus will not ruin the Plate Solve and Centering function, considering that you should do it with a high Binning in any case.
Fabio.

[AstroBernd]

Hello Fabio,
Thanks for the script and your valuable comments. I will use that.
Yes, and also an option in the Meridian Flip Monitor would be a helpful tool. Before or after the plate solve, doesn't really matter, unless there is a large image shift (like with some SC telescopes at high focal length).
Cheers
Bernd