It seems that it *might* be possible to build extra shutter release and AE-lock/AF-activation button (the '*'-button) in Battery Pack E1 (BP-E1). I removed the BPack-E1 from my EOS-3 some days ago and with resistance meter checked if any of the camera buttons can be "seen" from the contacts at the bottom of the camera. I mean the long row of (double)contacts, maybe 14 or so (can't remember now). It seems that the first (two?) contacts (counting 1,2,... from the right end of tha camera when looked from the photographers "seat") are ground, and the four last (closest to lens) are VCC. The contacts before the first VCC contact seem to be shutter button half-press and full-press (resistance becomes about 0 between ground and these pins when I play with shutter release). I also found the '*' button somewhere closer to the GND pins (though the resistance didn't go down to 0 ohms and seemed to change between ..20..50.. ohms, maybe due to the type of the switch). I couldn't find the focus point selector switch operation but I'm not sure if it exists in PBooster-E1 which has some controls (which controls by the way?). It seems that the main dial also can't be found directly so my quess is that communication between PBooster-E2 "new" buttons and body is done with some serial interface between camera and PBooster-E2 processors but communication with older PBooster-E1 is done with direct wires/connectors to the corresponding camera controls. Maybe even all communications with the new PBooster-E2 is done with serial interface but to keep compatibility with *both* boosters (and older EOS-1n) they have included both interfaces in PBooster-E2. So, Canon could make a relatively cheap Batter Pack (no need for CPU) with at least some controls in it. To have e.g. main dial would perhaps mean a CPU based implementation which might add a few dollars in the price. I may some day try to make those two switches in my BPack-E1 if I just find time (The BPack-E1 has all contacts in it!!). Just FYI if anyone is interested. regards Vesa _________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com. * **** ******* *********************************************************** * For list instructions, including unsubscribe, see: * http://www.a1.nl/phomepag/markerink/eos_list.htm ***********************************************************
