Archived posting to the Leica Users Group, 2001/01/12
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Here's my take on it Looking at the lens from behind with the red dot at 2 o'clock First cam is wedge shaped and at around 12 o'clock Used on the flex standard for meter coupling and on the SL2 for aperture readout in finder. Not used on the SL or the Rs Second cam is also wedge shaped, used on the SL and SL2 for metering. Not used on the Rs or the standard Third and fourth cams are just attached to and just inside the second cam It resembles a 2 step tab The the third cam is used on all the Rs for meter coupling while the fourth cam is used on the R4 and later cameras. I think it enables shutter priority and programmeb mode but am not sure since it's position may also be dependant on the speed of the lens. These cams are stamped from one piece of metal. Now here's my question(s) Why did they use both cams on the SL2 They could easily have added a tab to the lenses to correct the aperture scale RTS style and avoided a second coupling. And for that matter why did they switch to lower cam coupling on the SL. Infact they could have kept that one single upstairs cam all the way through the SL2 and still had aperture readout. I don't think it had anything to do with the Super Angulon but I may be wrong. See Ya Javier >From: "Randy Andrade" <smaugmra@abq.com> >Reply-To: leica-users@mejac.palo-alto.ca.us >To: <leica-users@mejac.palo-alto.ca.us> >Subject: Re: [Leica] Re:50 Summicron-R >Date: Fri, 12 Jan 2001 01:06:32 -0700 > >You are absolutely correct, Doug, that is exactly what I was asking in my >own deficient way. >Please tell me if I've got it straight. There are the two "normal" cams >that look like what one would think of when one hears the word cam...little >slopey thingies, for brevity's sake. Then there's the aperture control or >diaphragm lever. But the third cam is the stepped "out" section of the >metal that surrounds the rear lens element. This arc of metal runs about >1/4 >of the circumference, located inboard or radially closer to the center or >axis of the lens from the lower or second silver cam, (usually at about 3 >to >6 o'clock when looking at the lens from the rear in the normally installed >and locked position). Is this correct? Does this cam move something >inside >the camera body, or is it supposed to move something within the lens >itself? >Thanks for all the help! >Randy > >On Thu, 11 January 2001, Jim Brick wrote: > > > > > From the rear of the lens, two fixed (they don't move) metal ramp >(sloped) > > cams, one on each side of the rear element (very prominent, can't miss > > them), the third cam is a square metal block (between the two ramp cams) > > that when you move it, it opens up the diaphragm. > > > > Two ramps and a movable square block. > > > > Jim > >Jim, I think what you're describing as the 3rd cam is what Randy calls the >aperture control lever. As I understand it, Randy wants to know how to >determine if the 3rd metering cam is present. > >Doug Herr >Birdman of Sacramento > > _________________________________________________________________ Get your FREE download of MSN Explorer at http://explorer.msn.com