1972 Olympics in Japan produced fantastic sequential shots that were previously impossible to achieve. In 1973, Canon introduced the Motor Drive MF. The Motor Drive MF had its batteries (10 AAs) in a vertical grip that mounted to the front left (looking from the front). It had a maximum rate of 3.5 frame/sec and was much better suited to action / sports photography, especially when paired with the Speed Finder or Servo EE finder. A special cord allowed the Servo EE finder to draw its power from the Motor drive MF – thus making a much more compact setup than the original Motor Drive unit. The Motor Drive MF did not have a built in intervalometer, but the Interval Timer L (and later the Interval Timer TM-1 (Quartz) could be plugged into the remote control socket as could remote switches and a wireless control unit, the Wireless Controller LC-1. These all allowed either remote and / or unattended use of the camera. Later, Canon introduced the Power Winder F, a 2 frame/ sec power winder with a grip for ease of use. It used 4 AA batteries in the same battery magazine that the Canon A-series Power Winder A used. The Power winder F could use most of the remote switches that also fit the Motor Drive MF. The only two accessories that it could not use were the Interval Timer L and the Remote Switch 60-MF. While not as fast, The Power Winder F was smaller and lighter than the Motor Drive MF. Unlike many other professional-level cameras of the early 1970s, the F-1 required no modification or special custom fitting to attach the motor drives, one simply removed the bottom plate and screwed the motor drive in place. Backs The F-1's back was removable. A Data Back F (for the original F-1 and F-1n) or Data Back FN (for the New F-1) (which being mechanical is now incapable of putting the current year on a photo) or a bulk film back that could hold 250 exposures could be attached. The Film Chamber 250 could be used alone or with the Motor Drive Unit or Motor Drive MF (the MF's grip had to be removed and coupled via a dedicated cord). Eyepiece The F-1s eyepiece was threaded and could take a metal (later soft rubber covered) ring, an eyecup or several different diopter adjustment lenses. The Magnifier R and