I seem to have a fault with my Nikon F3, with a lens attached it fires the shutter on full advance with the leaver. Without a lens, I have worked out that
Nikon F3 Review | 5050 Travelog
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How to Use: Nikon F3 - Kamerastore - YouTube
Nikon F3 Exposure Memory Lock Button by didoriginal | Download free STL model | Printables.com