And this is my first experience photographing stars using a telescope (Sky Rover 115mmF7+Flattener). The other day there was a clear sky night but dedicated to learning and practising polar alignment, practicing various hardware and software system and tools, fighting all sorts of problems, etc.
Unguided CEM40 nonEC
The first target:
M51 30x30s L -- under terrible light pollution
Next, 3C273. Photons from 2,443,000,000 years ago. 4min exposure and stars as faint as m16.5 can be detected.
NGC5139 would be an easy target. Or not. I was trying to center the image using a few short exposures before running a sequence of long exposures. 3rd short exposures in, the whole image turned white. Raised my head, and aha, the naughty clouds had covered nearly the whole sky. End of joy.
So this is a single 8s exposure.
But I was awarded a clear sky in the morning when the two gas giants were shinning near zenith.
Went to set up the system and captured a few videos through 3X focal extender. After postprocessing, the result is not bad for this small-aperture 4.5in APO.
Clear skies!