Troubleshooting Astro pics

[Grim-Reaper]

Hello fellow photographers!

My girlfriend recently switched to a Panasonic G9. We both tried to get some astro shots to practice, as we are total beginners in this regard.
However - her images are showing very strange patterns I can't get my head round.
They were taken with the Panasonic Leica 15mm f/1.7 and the patterns are even visible on the finished long exposure image on the camera screen.

Things we looked into:
-Electronic vs. mechanical shutter, but on later sunset images with mechanical shutter the patterns were visible again!
-different RAW converters: Lightroom (newest version), Luminar 4, Silkypix 8, Darktable (last one to remove integrated lens correction)
-ISO - these were taken at extended ISO 100 and she did not take other astro images with other ISO settings
-the lens itself: Could this just be some flare/reflection of this specific lens? No filters used and in the later sunset images the problem occured similarly

Any help is appreciated! I'm gonna add two images. First one is developed less, second one is exaggerated to show it more clearly.

Thank you in advance!

 

[walter_j]

Try another lens. If the problem is still there - perhaps its a sensor issue. Turn off stabilization

 

[WhidbeyLVR]

Can you make the original raw file available on Google Drive or Dropbox (or equivalent)?

 

[Grim-Reaper]

Can you make the original raw file available on Google Drive or Dropbox (or equivalent)?

Sure, very welcome

In the sunset photo you might need to "provoke" it more than the astro pic, but there's some circular pattern in there as well.

https://drive.google.com/file/d/17noXtEgrozjSddvuTXZscNeq1s1evrQF/view?usp=sharing,
https://drive.google.com/file/d/1io8IO8UeMn3mIil5JkLQi9ga6cYW2rjR/view?usp=sharing

 

[spdavies]

Moisture condensation on front of lens?

 

[Grim-Reaper]

I don't think there was any condensation. Two separate occasions, long period of shooting and no problems on my Canon camera next to it.

 

[Stanga]

It's the stabilization. You can get this pattern on dark images.

 

[Grim-Reaper]

It's the stabilization. You can get this pattern on dark images.

My girlfriend thinks the stabilizer was turned off, but no guarantee. But that's definitely a thing we'll try back to back, thanks

 

[Mountain_Man_79]

It's the stabilization. You can get this pattern on dark images.

Is that a stabilization artifact specific to Panasonic’s? I rarely remember to shut off stabilization on my Olympus cameras when doing astro, and have never seen such a thing.

 

[WhidbeyLVR]

A similar effect (but with Nikon) was discussed on DPReview a few years back, but no definitive answer as to the cause.

My suspicion is that there is a small but real flare that is messing with the hue/chromaticity, and your adjustments to exposure are amplifying this small, real problem. I ran your astro file through DxO Photolab 4 with a neutral color, neutral tonality profile and the concentric rings were less obvious, but still there. I then used LAB processing to bring things up a bit without amplifying the chromaticity, then brightened the dimmer stars with a separate local contrast adjustment. The rings are still there, but much less noticeable.

Subscribe to see EXIF info for this image (if available)

 

[Neon Birding]

Perhaps this can help.
A lot of reviewers claim the MFT and G9 doesn't do good in low light. Depends on how low the light, and what exposure is being used. The reality is a RAW file for any specific camera can only hold so much data for color and exposure amplification. And that varies greatly among camera formats and brands.

Coming from DSLR, I had a lot of data to push in editing. Especially for landscapes at twilight. When I switched to MFT, I was challenged with less resolution, more noise at 3200 ISO, and the in-camera NR that doubles the time for exposure. What I found was, G9 could not be shot like a DSLR. So, by trial and error, and tips online, I found that nailing exposure is the key to getting any shot I wanted regardless of possible noise or blur.

With G9 there are many options and functions that interact and impact other functions of exposure. Settings like iDynamic, Picture Style, Highlights/shadows, exposure comp, and WB all interact for what exposure data will be captured. Boosting/reducing too much of one or another of these dynamic settings could cause noisy or color banded pics.

With that said, once you experience what exposure values work best for your application, you'll start to see patterns of what lighting conditions work, and the exposure settings that works best for your specific/unique lighting conditions: Unfortunately that from trial and error.

Modern mirrorless cameras can take amazing pics and video. But the great shots are the result of skills and techniques of the photographer.