My fascination with the F3 is centred around the many uses that it has been adapted for over the years.
I don't know of any other SLR camera/brand that has been used so extensively over such a long period of time.
Perhaps it's why the product was on the production-line for 20 years.
1. Extensively used & modified by NASA for both space and ground operations.
2. Used as the bases for the world's first professional-level digital SLR system by Kodak.
3. Was part of a system that was the 2nd digital SLR to be used on a Space Shuttle mission (the F4 was the first).
4. Was used & modified by the US NAVY for use on the Los-Angeles-class nuclear attack submarine fleet.
5. At least 8 different companies used the body for various types of pin-registration systems used for stop-motion.
6. Used and adapted for at least 2 Polar expeditions undertaken by Japanese explorers.
7. I'm sure there's more that I'm yet to find out about.