Here is a target that has defeated me ages - the Iris Nebula and the nearby clouds of dust.
This was a quick test run of 60 x 2min subs at ISO 1600 using an unmodified Canon EOS R on a Takahashi Epsilon 180ED under a 20.8 mag/arcsec^2 sky (Bortle 4):
Larger version is in the gallery here:
https://www.cloudyni...on-eos-r/large/
I have previously documented the issues I had with with similar faint targets using the Sony A7S (purple and green swathes) and the Nikon Z6 (coloured concentric banding):
https://www.cloudyni...egreen-swathes/
https://www.cloudyni...ting/?p=9610122
In contrast I was astonished at how easy it was to calibrate and process this set of data from the Canon EOS R. I didn't even need to do a PixInsight DBE (DynamicBackgroundExtraction). The only "trick" I had to use was colour matched flats (flats matching the night sky background) because in common with the Sony A7S and Nikon Z6 the sky flats taken at dusk did not do a good job of calibrating the lights taken at night. This is partly or totally caused by small non-linearities (1% or less) in the sensor's response curve.
I mentioned the Canon EOS R here in the thread on colour matched flats: https://www.cloudyni...udy/?p=11333190
So far, I'm very impressed with my new Canon EOS R.
Mark
Edited by sharkmelley, 10 September 2021 - 08:39 PM.
