Comet Halley. December 31, 1985.
5 minutes exposure. 3M 1000 slide film. 5" f/5 refractor at prime focus.
By the end of December, the comet had almost completely disappeared into the evening twilight. My final pre-perihelion observation was on New Year's eve. On this night, the comet was still easily visible despite the twilight, as a magnitude 4.8 object with a very faint 0.5 degree tail.