Reviews of Canon Power Drive Booster E1, Ni-Cd Charger E1 and Ni-Cd Pack E1. In this issue, the focus is on three types of accessories for users of Canon's top-of- the-line camera, the EOS-1N professional 35mm AF SLR camera. The accessories are the Power Drive Booster E1, the Ni-Cd Charger E1 and the Ni-Cd Pack E1. Except for the Power Drive Booster E1, the two other E1-type accessories can also be used for the pellicle-mirrored Canon EOS-1N RS camera which has a permanently built-in Power Drive Booster E1. All three E1 accessories can be used on the original Canon EOS-1 camera as well. Power Drive Booster E1 This power attachment unit raises film advance speed to 6 frames-per-second (fps) for rapid fire continuous shooting when it is fitted to the Canon EOS-1N camera which has a built-in 3fps firing rate. For the original EOS-1 camera, which has a built-in 2.5 fps film advance, the firing speed is boosted to 5.5 fps. << Back to Main . 1 . 2 . 3 . 4 . 5 .