Archived posting to the Leica Users Group, 2004/02/09
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Stan Yoder <vze2myh5@verizon.net> wrote: > As an 'M guy' who just bought an SL, could 'yunz' (as we say here) set me straight on this cam > business? Stan, the cams refer to the commumication between the aperture ring and the camera body's meter. The first lenses, for the Leicaflex Standard, are one-cam lenses. They have a control arm that operates the lens' diaphragm, but this is not a 'cam'; it's at about the 3 o'clock position at the back of the lens. The first cam is a silver-colored sloped arc at about the 12 o'clock position on the back of the lens. This cam is directly connected to the aperture ring, and tells the camera body what the actual aperture set on the lens is. This was used originally by the Leicaflex Standard's non-TTL light meter. It's also used by the SL2 for the viewfinder aperture indication, but it's not used on the SL at all. The second cam looks like the first cam but it's at the 6 o'clock position on the back of the lens. This cam is used by the SL and SL2 TTL meter; it tells the meter how far the lens will stop down from full aperture. The 3rd cam is a stepped tab 'inboard' of the 2nd cam. It's typically a separate piece of black metal but in at least one case (21mm Super-Angulon-R) it's milled from the same stock the 2nd cam is made from. This cam tells R3 and newer bodies how far the lens will stop down. Doug Herr Birdman of Sacramento http://www.wildlightphoto.com - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html