Mike, The MD-3 is/was a lesser expensive motor drive for the F2. I'm not sure what features it has but I'll bet it doesn't rewind your film. It may have only one film advance speed as well. I have and MD-2 and just love it. The MD-2 has the rewind feature and a selection of film advance speeds. If you use the MD-2 with the MF-3 camera back, the rewind shuts off when the film has passed the pressure plate. This prevents the film from getting ripped to shreads. Good luck with your decision.
- MD-3 spad
- Wermeyer