I'm getting up to speed using EKOS on an Pi running StellarMateOS. I am generally getting the hang of things but I have some needs that seem to be outside of EKOS wheelhouse so I thought I would double-check here.

I shoot with a 72ED refractor, a Nikon D750, a DeepSkyDad focuser and a Star Adventurer tracker. Although an eventual goal is to do some deepsky photography utilizing SM/EKOS, I also do lunar and solar photography (white light, using Baader film filter). What I am looking for is the ability to do autofocusing on those subjects.

Based on my understanding of the EKOS documentation for the focusing module, it appears to only handle autofucusing for stars. Am I missing something? Any chance its native capabilities can be adapted for solar/lunar?

Thanks,
Nate

Hi Nathan,

The Autofocus routines are designed to use stars to focus. HFR, HFR Adj, FWHM and Number Stars all rely on star detection to work. Fourier Power doesn't use star detection per se but relies on certain properties of star fields so I doubt it would work well on the moon or sun - but i've never tried it. Ideally, i think Autofocus would require different algos for solar / lunar and planetary focusing.

You can use the manual focus in / out buttons to achieve focus, however.

I would add a note that is for me a big problem.
During the focus loop (not autofocus) is impossible to move inner or outer the focuser. You have to stop the loop, move the focer and then loop again to check it

Hi Alessandro,

I've just fixed this bug. I haven't merged it yet as I want to do more regression testing on it tomorrow. Although the fix is quite simple it is in a core part of the focus system and I want to minimise the chances of breaking something else.

The change is in invent.kde.org/education/kstars/-/merge_requests/1130

Are you able to take bleeding-edge changes once its merged?

heh, I thought I was losing my mind last night. Glad to hear it wasn't just me. (and that it is known and being fixed!)

John,

I pulled your fix and tested with simulators. I was able to focus in/out while looping frames without any issues. Would like to test under the night sky but weather doesn't allow.

Oh, AFAICS it's been merged right now!

I just merged the MR!

Hopefully no issues with it.

For anyone else with same interest, i.e., autofocusing on the Sun or Moon, I did find an INDI solution: CCDCiel. Installing it on the Raspberry Pi 4 I have running StellarMate OS, once I use the SM Web Manager to start indiserver with profile for my camera (Nikon D750) and focuser (DeepSkyDad AF3), I can connect with CCDCiel, set autofocus mode to Planets and then start Autofocus and it appears to do a pretty solid job of getting a sharp focus. CCDCiel has a lot of overlap with EKOS/KSTARS so not sure yet which I will end up using for imaging but even if I just use CCDCiel for solar/lunar autofocus, it'll be worth having.

Autofocusing on stars has been the only thing supported. That said, John and I were thinking of looking into whether measures like Fourier Power that John added, or another one I have in mind (not yet added) might work for the Moon or Sun.

If anyone wants to try and report back, please give a shot at focusing on the Moon with the Fourier Power measure and report back (bad weather here). You'd definitely want to make sure that you're not overexposed--we expect that Fourier Power will not work well with overexposed/clipped pixels.

I am giving this a try now as the wind from yesterday has died down and I've got excellent viewing conditions.

However, as I am still new to EKOS/KSTARS and have not yet used it at night, I'm unclear whether I am doing this correctly. I did set the Measure to Fourier and I started the process with the focuser reasonably close to focused but not close enough to appear sharp. I am taking 0.001 second shots at ISO 100 with a 2 second delay. However, while images at this exposure look close to correct on the camera (could go a bit slower and still not have blown highlights), in EKOS it appears totally blown out and only if I shift the midtone slider up a bit does it appear close to a proper exposure. I am not sure how to do that in the image viewer on the Focus tab so everything is so blown out I can't tell what progress the focusing increments during Autofocus are actually doing.

I am also not clear whether there are steps I need to take during Autofocus to help with source selection, whether to use full frame or a subframe and, if a subframe, what to select, e.g., an edge, a sunspot, etc.

Suggestions?

The fitsviwer's functionality in Focus is restricted (space mainly I guess). However, you can pop open a full fitsviwer by clicking this button. This launches a full fitsviewer where all the functionality is available...


How did the rest of the imaging session go?

I updated my Kstars to the latest available kstars-bleeding_3.6.9+z+stable~202403030838_arm64 but the problem is still present