The comet at its highest but also worse twilight, zoomed in with the Nikon D7000 and 3 sec images, stack of 10.

Then immediately started on another set, of 13 images, 3s each. Used the zoom lens set wider. Used mode command in Photoshop to reduce from 32bit to 16 bit and that's when all the sky noise came in.

Same image, this time left at 32bit, and then screen-captured off my laptop and then imported to Photoshop to get around the 32bit-16bit conversion trouble.

Selfie, using my PowerShot. Twilight in back, and a streetlight.