Created attachment 160510 [details] Refocus diagram # Reason for the request Shooting nebulae in narrow band I often move manually the telescope to a closer bright star for focusing so I can get a faster focuser procedure. When I start a sequence, if I reach the focus limits (Refocus every x minutes, Autofocus if ΔT° > x, etc.) the procedure often fails because no sufficient stars are found. # Proposal I’d like to see a new parameter in preferences: “Focus magnitude limit” for refocusing, then if a refocus is required, KStars could search for the closer star or stars cluster brighter than “Focus magnitude limit” using the observation planner module and focus on it.
Created attachment 160511 [details] Guide & Focus Limits
(In reply to Matteo from comment #1) > Created attachment 160511 [details] > Guide & Focus Limits Hi Matteo, Your proposal sounds interesting. I'm currently thinking about a different but possible related request from someone interested in photometry who would like to focus on a reference star before imaging a different target star. So I'm thinking I might be able to do something that works for both of these requirements. What I'm thinking (and these are very preliminary thoughts) is that I could introduce the concept of "Focus Target" to complement the current "target" (which is really a "Capture Target") that can be set in the skymap, scheduler, etc. For most folks the "Focus Target" and "Capture Target" will be the same, as they are today in Kstars. So: Setting up a scheduler run would then require a "Capture Target" and an optional "Focus Target" to be setup. If there is no "Focus Target" then Kstars operates as now. If a "Focus Target" is set then... 1. A focus run would become: a) Align to "Focus Target" b) Run Autofocus c) Align to "Capture Target" 2. When focus limits, e.g. time are reached, a) Align to "Focus Target" b) Run Autofocus c) Align to "Capture Target" The Scheduler has functionality to coordinate Align and Focus so would be good to utilise that. The Autofocus would more or less use the current functionality: 1. If multi-star focusing then after alignment just run focus as normal. Autofocus failures would be handed back to the scheduler as now. 2. If single-star focusing then Align will tell (somehow) which star to use (star nearest the centre of the FOV) or the user selects the star as appropriate. This bit needs more work. The reason I think a user specified target will work better than have Kstars try and work out a suitable star above a certain magnitude is that there are endless reasons why Kstars will pick a suboptimal star from the user's perspective (star too bright and saturates, star too low in the sky, tree in the way, star too near Moon, etc etc). No doubt these issues can all be coded around but I think its easier to let the user select the "Focus Target". Anyway, these are just some initial thoughts. I'd be interested to hear your thoughts. Best, John.
(In reply to John Evans from comment #2) Hi John, I like the “Focus target” concept: a little effort to optionally chose the target but a great control and especially a predictable result (seeing the first focus result when you start the sequence). For me is a go. Thanks, Matteo
Hi Matteo, Thanks for the reply. Let me think some about it. I'm familiar with the Focus module, less so with Align and Scheduler, so I need to do some research on what would be needed in these components. I'll revert on this thread with more information. Regards, John.