Here are two images I made in 1985 during the last apparition of Halley's comet. These are about 45 sec. unguided exposures made with f/1.7 50mm lens and processed in D-19 (2475, Halley-1) and D-76 (Tri-X, Halley-2), if I recall correctly. Both images are almost full-frame, viz. scans of about 80% of the 35mm frame.
The exposures were made on a moonless night with a clear and cold New Mexico sky and no exterior lights to interfere by brightening the sky.
I believe the 2475 was about ten years out of date at that time and had been kept frozen until use. I post these here just to add interest to the discussion.