A month ago I reported missing keyword for Filter in the FITS header. I shot more flats today and the same thing occurred - some files (a majority) were missing the Filter keyword in the header. (Causing WBPP to sort them as "no filter".

There was no response to my last post on this topic. Am I the only one? My flats are saved to my indoor laptop (client) rather than the Pi on the telescope. Camera is a QHY268M with the QHY FW3 filter wheel. Filters change as expected, filter name gets written to filename as expected, but only intermittently to the FITS header.

Anybody have any ideas on this? In this case all the exposures were short, in the neighbourhood of 0.05 to 0.12 seconds. (new flat source much brighter than expected - still experimenting)

This was with an updated Kstars - 3.5.8. Stable, Build: 2022-03-24T22:52:45Z

Same experience here. Seems to be limited to Flats. But strange thing is that it is not constant for one filter. For each filter, some files have the Filtername written in the FITS header, others don't.
I am still on 3.5.7, but did not have this problem in the past.
Using KStars on Mac, exposures are 2-10 secs.
Like you say, very annoying, because you now have to calibrate the flats manually before you can use the automated WBPP script.

Willem, I noticed this issue first with Flats and 3.5.7. I updated to 3.5.8 three days ago, just before a rare clear night two nights ago. I noticed the issue when PixInsight's WBPP script reported a number of Flat exposures fell into a "No Filter" category. This time a few light frames were effected too. Filenames properly show filter used but FITS header is missing the Filter keyword. Last time I think only Flats were involved.

I'm hoping for a resolution as individually adding the proper keyword and value to each file is time consuming. I haven't the skills/experience to write a script to automate the process.

David, yes, what you describe is exactly the same behaviour as what I experience as well. It looks like it is an error introduced in 3.5.7 then. And I use ZWO filterwheel, run KStars on a MacMini (Mojave) and store files locally. Since our setup is quite different, it seems unlikely that this is driver or OS related. Hopefully this will be picked up and corrected in future updates. I will try to see if I can post this as a bug.
In the meantime I have been doing some searching on the PI forum and found a nice workaround. Here in this thread they show other examples of acquisition software not writing FILTER keywords to the FITS header. Towards the end of the thread, someone has created a script to do this on whole batches of files at once. I have just installed that script and it works very well. My WBPP is currently crunching a whole bunch of files, many of which have been edited using this script. Not ideal, but a workable workaround.
Oh, and the script works so familiar, that it might open up possibilities to use FITS-header info even more extensively. For your convenience, attached is the script file.Let us know if this works for you too.

Willem Jan.

I've posted this as a bug on Github: github.com/indilib/indi/issues/1649

I saw the same in my images. Some have a Filter i Fits Header, others don't. This is with a new install, Kstars v 3.6.0 on a Raspberry Pi 4, ZWO ASI294MM with ASI mini filter wheel. It happens for Lights and Flats
Also, I noticed that the exposure time for Lights and Darks appears differently in the FITS header. A 300 s exposure time can be either
EXPTIME 300.
or
EXPTIME 3.000000E+02
Not quite consistent

I hope these issues get resolved

/Wim

Using Mac OSX KStars 3.6.1 and no filter field in the FITS header either.

Fyi. I installed astroberry (downloaded last week) on a reformatted 64 GB SD card and have tested my setup with that. This version of astroberry runs Kstars 3.5.5, which is much more stable. I only collected very few exposures, but they had FILTER in the Fits header. As soon as I get clear skies I will run a proper sequence and confirm if the older Kstars version writes the filter keyword. If no clear skies, I will collect flats during the weekend. Either way, by sunday I should have more answers.

Cheers,

Wim

I had a chance to do some imaging tonight with the fresh install of Astroberry (Kstars 3.5.5). All of the images that I've checked had the FILTER keyword in the Fits Header. This is the same hardware as before (Raspberry Pi 4 with 64 GB SD card, same gear attached). For me at least, the problem only appeared after reinstalling the OS and upgrading to Kstars 3.6.0. When I find the time, I will install Astroberry on a spare SD card and update the version of Kstars on it from 3.5.5 to 3.6.0. Perhaps I will find time this weekend.
Cheers,

Wim

Last night I took 60 images. When I loaded them into Pixinsight only the first three had the filter name in the FITS header. I have no idea why it stopped recording it after the 3rd image.

I finally got around testing 3.6.0 in Astroberry.
Here's my configuration:
Raspberry Pi 4 with Astroberry 2.0.4, upgraded to Kstars 3.6.0 (sudo apt update, sudo apt upgrade)
Camera: ASI CCD (ASI294MM Pro)
Guide camera: ASI CCD (ASI290MM mini)
Mount EQMOD Mount (SW AZ-EQ6)
Focuser: Pegasus Focuscube
Filter Wheel: ASI EFW (ASI mini filter wheel with 5 positions)
Auxiliary: Astrometry

I took a quick daytime sequence of 10 10s Luminance images, 10 10s Red images and 10 10s Green images, all Lights at bin 2x2, 30 exposures in total.

From the FITS header in Kstars Fits Viewer it seems that all files have the FILTER keyword.

Edit: after ftp from the Raspberry Pi to my stationary computer I can see that all files are exactly the same size, and the few files I have opened in PixInsight all have the FILTER keyword.

Over the last two weeks I've run into this issue of the filter not being written to the FITS header. Since I've had no changes to my environment I had assumed I may have inadvertently flipped a software switch somewhere along the way but I've no idea what that might have been. I've just finished importing a few hundred images I've taken with EKOS (3.6.0 Stable running on MacOS 12.6 (Monterey)) and there is no filter record in the FITS header. 60+ other records but no filter information. This somewhat complicates PixInsight WBPP but thankfully there are easy workarounds short of editing the FITS header. This is happening for all my Light and Flat frames of all kinds of exposure lengths. I've been using EKOS/KStars for over a year and haven't run into this before.

I see this thread goes back a few months and predates the current release. Also the bug posting on GitHub hasn't seemed to advance but I'll post there as well.