This is a fragment of my recent photo of the pinwheel galaxy (M 101):
- Canon EOS 70D (astro-modified)
- Canon EF 100-400 mm f/4.5-5.6 L IS
- 400 mm
- ISO 2000
- 22 frames @ 2.5" each
- 5 dark frames subtracted
During the observation, the sky was clear, the object was near the zenith, and temperature was around +10 °C (+ 50 °F).
So, what should I do in the future to make my astrophotography less noisy? Is this maybe thermal noise? Thank you.