Taking two half frames instead of just one is a enjoyable way to do diptychs. The challenge is of course to see the diptych at the photographic moment.
Technical info: Agat 18k half frame. Lucky SHD 400 developed in D-76 1+1, 8.5 min (3 inversions every 30 sec). Fujimoto G70, El-Nikkor 50/2.8, Forte Polywarmtone FB in Neutol WA.