Nice catch. I used to do a lot of that a fair while back. Here are a
couple of shots at various bandpass.
I was inspired by JJJ (Jeanette) who used to do a lot of fantastic widefields at the time. I had an old Pentax lens and shot very dark fields even tracked at 15min exposures for a while not understanding that the lens I was using had a camera controlled aperture so the iris was almost closed when the lens was separated from the DSLR.
Bit of plastic shim to keep it open eventually sorted that out.
