2022-10-06 M31 Andromeda Galaxy

An attempt at photographing Messier 31, the Andromeda Galaxy, under bortle class 9 skies.

I'm pretty excited that I was (barely) able to capture some faint detail of Messier 31s arms under this abysmal light pollution. A fun challenge, but I want to try this lens in more rural conditions next.

The configuration listed above is the result of quite a few attempts at different exposure parameters. I've listed some of my key takeaways below.

• The Takumar 300mm is a great lens considering its age (1965-1971) and price, but at f/4 it is very soft and produces incredible amounts of vignetting.
• I never got rid of the awful fringing. Either I'm unable to focus properly, or this is simply an artifact of the lens. I should get my hands on a Bahtinov mask.
• Exposing at f/4 ISO3200 produced a worse result than f/4.8 ISO1600. The light pollution was so strong that letting in more light drowned the entire galaxy in an unrecoverable amount of pollution.
• Shooting at 300mm focal length without tracking is limiting as the longest functional shutter speed is about 1 second. I don't want to stack 1000+ 1s frames to achieve a more reasonable exposure, so I should probably get a tracker at some point.

Comparison

My last attempt at capturing Messier 31 can be seen in 2021-12-25 Andromeda, but here is a quick side-by-side comparison where almost all parameters differ wildly.

Metadata

• Location
  • Name: Oslo City, Norway
  • Lat Long: 59.92, 10.72
  • Datetime: October 6th, ~22:30h
  • Bortle Scale: Class 9
• Gear
  • Camera: Fujifilm X-T1
  • Lens: Pentax Takumar 300mm f/4
  • Tracking: None/Tripod
• Exposure
  • Aperture: f/4.8
  • Focal Length: 300mm
  • Shutter Speed: 1/1s
  • ISO: 1600
• Processing
  • Light Frames: 100
  • Raw Converter: RawTherapee
  • Stacker: DeepSkyStacker
  • Total Exposure: 1min 40s
  • Editor: GIMP