In article lid, Aidan
Karley wrote:
When I've done night-sky photography before, and cave
photography, I generally try to make sure to get an "indexing shot" of
a bright subject near start and end of each film.

Of course, this is buggered up if your film-wind mechanism is
advancing 1+bit frames per frame. I really ought not drop the camera off
cliffs so often!

--
Aidan Karley,
Aberdeen, Scotland,
Location: 57°10'11" N, 02°08'43" W (sub-tropical Aberdeen), 0.021233