×

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

Bi-monthly release with minor bug fixes and improvements

Auto-Slew To Bright Star For Autofocus Routine.

  • Posts: 1309
  • Thank you received: 226
I have talked some friends into trying KStars and one has brought up a feature that he uses and is reluctant to give up. I could be wrong, I haven't personally explored autofocus much, but I don't believe this is in KStars at this time.
Essentially during his autofocus routine, the software he uses will slew to a nearby bright star, ~4th mag to focus on before returning to the target. It can do this periodically or when temperature changes exceed a set value. This procedure should help anybody attempting to image a region with few or dim stars and I suppose a brighter star can be more accurately focused with. Could such a feature be implemented in the future?
7 years 3 weeks ago #14948

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

  • Posts: 456
  • Thank you received: 76
What sort of telescope + filter + conditions is he using? I have a C11 at f6.3 and I've never needed to slew to a bright star to focus. My FOV is about 27x30arc min and Ekos aut-focus never has any problems finding a star with 2/3 sec exposures. I guess if your friend has a much narrower FOV and under light polluted conditions then it could be different.
7 years 3 weeks ago #14996

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

  • Posts: 1309
  • Thank you received: 226
I can't comment on his reasons, as I expect his equipment will have no issues finding a suitable star. But he owns a Celestron HD 1100 @F/10 and Takahashi FSQ106 @ F/3.64, on a Losmandy G11. Plus, SBIG ST-8300M, Starlight Xpress SXVR-H18 cameras, and a comprehensive filter set.
7 years 3 weeks ago #15000

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

  • Posts: 158
  • Thank you received: 32

KStars will autofocus on a filter change, and when the HFR (Half Flux Radius) exceeds a given threshold. No slew is needed in order to do this. That would be a waste of imaging time to slew away, focus, then slew back, center, etc. The sensor on the camera you mentioned is sensitive enough that this action is unnecessary. The telescopes in question are both good enough that this also should not be necessary. This feature should not be added, as I think there are more important things in their backlog.
7 years 3 weeks ago #15001

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

  • Posts: 1309
  • Thank you received: 226
I had a chance to ask him why he finds it necessary to spend the time focusing on a bright star. And the reason was he is imaging with very fine, 3nm narrow band filters.
7 years 1 week ago #15437

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

  • Posts: 158
  • Thank you received: 32
You don't need to slew to a bright star to do that.
7 years 1 week ago #15438

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

  • Posts: 456
  • Thank you received: 76
Same here with a 7nm HA filter. I just use a longer exposure, like 6 or 7 seconds or so, the ekos focuser has no problem.
7 years 1 week ago #15439

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

Time to create page: 0.239 seconds