For #GlobalEncryptionDay 2025
Privacy is a human right!

Privacy gives us the freedom of autonomy

Encryption protects us from the violation of our other rights.

Homework between #Brussels & #Rennes with #Gimp #GnuPG #KeyArt #Cli #Linux
#RefugeesWelcome #Privacy #HumanRights #DigitalRights #GlobalEncryptionDay2025
#Bretagne #Belgium #NoOneIsIllegal #NiemandIsIllegaal #BZH #Breizh

Comet 2025 A6 Lemmon

The conditions on Sunday (19.10.2025) were good, so I drove out to photograph the comet C/2025 A6 Lemmon. It was only visible in the camera and not to the naked eye.

This image is a composite of the comet, stars, background without stars, and the foreground. Except for the foreground, the image was created from 171 frames (14 minutes and 15 seconds of exposure) using #Siril, including #StarNet. Post-processing and final composition were done in #GIMP.

Nikon Z50, Nikkor 17-28/2.8, 28 mm, f/2.8, 171×5 s, ISO 1600, tripod
#comet #lemmon #astrophotography #photography #nightscape #germany #digikam

Andromeda Galaxy

This image of the Andromeda Galaxy (M31) was not planned. I saw M31 on the Stellarium app while outside for Comet Lemmon and thought, why not? I took a few photos but gave up early because I thought my equipment would not be enough to get any details. Turns out I was wrong, and you can get details even with a 105 mm f/2.8 macro lens on a crop-sensor DSLR.

This was just 23 photos, resulting in 46 seconds of exposure. Post-processing was done in #Siril with #StarNet, followed by #GIMP and #Darktable. Next time, I’ll know better!

Nikon D500, Sigma 105mm EX DG OS HSM, 105 mm, f/2.8, 2 s, ISO 3200, tripod
#Andromeda #Galaxy #astrophotography #photography #germany

Milky Way Section

A section of the Milky Way from 118 images (9 minutes 50 seconds exposure time). I played around with the #StarNet integration in #Siril to bring out the structure of the Milky Way independently from the stars.

Nikon D500, Nikon AF-S Nikkor 50mm f/1.8G, 50 mm, f/1.8, 5 s, ISO 3200, tripod
#MilkyWay #astrophotography #photography #germany #digiKam #Darktable #GIMP

The Pleiades

My first attempt at deep-sky photography with the Pleiades.

Since I do not have proper astrophotography equipment, I set up my trusty DSLR with my longest lens with a large aperture (a 105 mm f/2.8 macro lens) and put it on a simple ball head on a tripod. Then I went to an area with low light pollution, pointed the camera at the Pleiades, and let it rip. I had to adjust the framing from time to time, as I did not use a tracker. As soon as I started getting cold and did not want to stand around anymore, I went home.

I loaded everything into #digiKam and sorted out all images where the camera had moved during the shot (which were too many). The remaining 177 shots were converted with #Siril to a FITS sequence, registered, and stacked. Another image did not survive the process, so the final image contains 176 photos (amounting to 5 minutes and 52 seconds of exposure time). After some image magic with Siril (green-channel denoising, asinh transformation, color calibration, etc.), I loaded the final image into #GIMP (including #GMIC) for cropping and contrasting, and then #Darktable for denoising and getting the final look.

The most difficult part? Getting the macro lens to focus at infinity... Thanks to the aforementioned amazing open-source projects, processing the images was relatively painless.

Nikon D500, Sigma 105mm EX DG OS HSM, 105 mm, f/2.8, 2 s, ISO 3200, tripod
#pleiades #astrophotography #photography #germany