I use my Raspberry 4 with astroberry (EKOS/KStars) since roughly summer 2020. I never updated anything and it worked fine for me. I always use a Canon600Da as imaging camera and since day one I saved the files as RAW (cr2) on the SD card of the Raspberry. Reason for RAW is that I usualy took at least the dark only with the camera in a box. So those are always Cr2. And I heard some issues that sometimes PixInsight stated that the fits lights and Cr2 darks are not the same size resolution wise. To avoid that I took all my pics in RAW format.
Due to an issue I got with a new ASI178MM I wanna use for vids with firecapture I decided to update the whole system to the newest version.
So since this update a few weeks ago I use KStars Version 3.5.5 with Build 2021-10-10T01:43:20Z as it says in the info section.
So whats my problem? First let me explain how I use the Fitsviewer in the past and what I remember to see in the old version
Usualy I got a Black and white (unbayered) picuture and a not stretched view. I than used the histogram to roughly set the exposure to the first 1/3 of the histo. That was my workflow and it worked
Since the update I recognized thats the Fits Viewer shows colours. No big deal. But at the first night out it also seems that my exposure and ISO changes has no effect on the picture FitsViewer showed me.
So it was some kind of guess work and my experience to set my exposure to the correct point.
Yesterday I took some time and tried to investigate the issue. I know that there are the option to setup the FitsViewer and believe my I checked and unchecked them all but that changed nothing.
Below I uploaded two pictures of the last night I used my gear. Both pichtures are made under the same conditions just a few minutes apart. I loaded them into the viewer to demonstrate you what happens
180s / ISO 1600 Also visible are the fits viewer options. No auto stretch, no auto debayer are the most important ones. Also the stretch button in the lower left corner is inactive. So it should be the linear version of the CR2 file as it was in the past.
240s / ISO400! Believe it or not this image should be way darker than the first one (~60s ISO1600 equivalant vs. 180s ISO 1600). But in the fits view they look identicaly as a stretch is applied. Also, and this is much worse, the histogram looks very similar but not identicaly.
To be honest I have no clue what is going on. I would be happy to get some ideas how to approach that issue. I am not very familiar with linux so If you need something out of the system it would be great if you also can tell me where to find the stuff.
thanks for your answer. I already tried the non linear histogram as well as forcing fits viewer to open each pic in a different tab to force the histogram to update. Both things did not work.
Also changing from Cr2 (RAW/Native) to fits did not change the strange histogram behaviour.
Losmandy G11 with Gemini 2 controller
QSI 583/683 monochrome camera with filter wheel
Starlight Xpress Lodestar X2 guide camera
Microtouch Focuser controlled using Arduino UNO emulating Feathertouch controller
Raspberry Pi 2GB with Raspberry Pi OS 32bit
as visible in the screenshot there is no stretch applied on purpose. Means the button on the lower left isnt pushed and the autostretch option is also off.
So there is nothing I can undo in terms of stretching.
But both pictures are obviously stretched somehow because they look absolutely identically even they are different un exposure and open them in a usual raw viewer also shows me different pictures and histograms.
Hope that answers your question as detailed as possible.
I tried fits yesterday and Maria is my witness it did not work. I still got an 8 bit histogramm.
I know it is a weird problem and Maria help me a lot yesterday via screensharing but we were not able to got a matching histogram which clearly represents both pictures.
If you need additional information or even the two raw files I used to create my screenshots in my first post let me know
Okay but is it the 8bit conversion which makes them look so identical? In this way it is useless to determine if the exposure is correct.
FITS is no option for me because at least the dark frames are taken with the camera alone and so they are always CR2 files.