Archived posting to the Leica Users Group, 2001/06/07
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]This is the way it is on ALL M cameras. Good explaination Marshall. Dennis Marshall Hunt wrote: > My Ms (M3, M4-P) have 4 rails. The pressure plate rests on > the outer rails, and the film travels over the inner rails. > The film travels through a space defined by the outer rails > longitudinally, and the difference in height between the > inner and outer rails, vertically. The emulsion side does > not touch anything in the picture area, and the shiny side > barely touches the pressure plate. (On my cameras you can > see the abrasion where the plate touches the outer rail, but > no abrasion in the center of the plate from the film).The > pressure plate does not depend upon the film for support. > Even my Zorki has 4 rails. Did Leica remove them for the M6? > I doubt it. Hunt. > > Dante Stella wrote: > > > > The pressure plate is not flexible. It rests on the film, which rests on > > the inner guide rails. When there is no film, it rests on the outer guide > > rails (which are slightly raised). This is pretty conventional with > > modern motorized SLRs, at least as far as I can tell. Too much force > > against the film would be hard on the motors, I think. > > > > My M3 has no outer rails, and the plate rests on the film plane rails with > > no film in it. > > > > On Wed, 6 Jun 2001, Mark Rabiner wrote: > > > > > John Collier wrote: > > > > > > > > I can only speculate but perhaps the flange to film distances are the same. > > > > The difference may be in the measuring technique. If Hexar measures from the > > > > bayonet flange to the pressure plate, this would give a greater distance > > > > than Leica's nominal 27.8mm which is to the front surface of the film. > > > > > > > > John Collier > > > > > > > ><snip>