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

Bi-monthly release with minor bug fixes and improvements

Focus on roundness

  • Posts: 43
  • Thank you received: 4

Focus on roundness was created by ecloud

The modern newton style telescope uses off-axis secondary mirror which could make the unfocused spot (a tiny ellipse) show the minimum HFR.
So the HFR could not represent the correct focus spot.
In my F4 Mak-Newt, the minimum HFR spot is always a vertical ellipse. I need to move the focuser a little out to get a proper round disk. This correction will only increase 0.1-0.2 HFR.
So I suggest to add roundness as for the Y value of the curve so that we can change monitoring from HFR to roundness when we like.
So the focus progress would be like that:
move focuser in one direction based on the HFR when HFR > 1.5 (a parameter)
received first <1.5 HFR
change Y value to roundness, calculate roundness instead of HFR
move focuser in the same direction and record roundness
received maximum roundness
move focuser back to meet the maximum roundness

I hope such function to be added into the focus module as an option.
Thanks.
The following user(s) said Thank You: Jasem Mutlaq, Spartacus
Last edit: 4 years 8 months ago by ecloud.
4 years 8 months ago #40813

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Replied by Jasem Mutlaq on topic Focus on roundness

Nice idea. Do you have any background in programming? We are very limited on resources and would appreciate more developers to step in.
4 years 8 months ago #40839

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  • Posts: 43
  • Thank you received: 4

Replied by ecloud on topic Focus on roundness

I do but not on C++
I'm not sure whether I could handle it or not.
4 years 8 months ago #40858

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