I am in awe of a photographer who can do that! It is incredibly hard to get the aperture/speed/ ASA settings right for the ‘dark moon’ part. The light is radically different brightness from the illuminated crescent. I read everything I could about settings for a lunar eclipse and it boiled down to “take one shot at every possible camera setting and find out which ONE comes out!” I did that once. Digital camera, of course. Cannot imagine using a bunch of film to do that.
THEN… once you know the ‘dark moon’ settings that work, you can attempt to take the multiple-exposure shots and change settings in mid- eclipse when it goes dark, and back again when the illuminated crescent appears…. all without spoiling anything on the multiple-exposure shot overall.
Of course, then there is Photoshop… for the lazy.