Olympus Pen FT half frame camera
Disc Shutter
Viewfinder
Film Transport
Pen-FT disassembly from my book: "Restoring the SLR"
Pen-FT disc Shutter made of corrugated Titanium disc
Related
Article in
Optomex
Requires timing alignment
Download Optomechanix July-Sep 2018
for a brief history of camera design at Olympus, and Pen-FT design