Archived posting to the Leica Users Group, 2008/05/12
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Thanks to all, I already know that. My question is not about the framelines and I don't need to adjust the Rokkor or to replace the adaptor on the CV. My question is about the _actual_ focal lengths of the M-Rokkor 28 and the CV 1.9/28. At least one of them is not a 28. Best wishes Jean 2008/5/12 Geoff Hopkinson <hoppyman@bigpond.net.au>: > Jean, it can get confusing with the M8 frame-lines. > For a 28 mm lens you need the 28/90 pair to display. The 28 frames show a > field of view on the M8 that is narrower than on a film M. This is because > the sensor is smaller than 24x36 and so it effectively crops the image. > With > a 28mm lens you are getting approximately the field of view of a 37mm lens > on a film M. > If you have a good 28/90 adaptor on your CV it should bring up the 28/90 > frames. If it doesn't you might be able to replace it. Not every adaptor on > the market is of equal quality. I have one CV adaptor that brings up the > right frame-lines and one 'no name' brand that does not work properly. You > should ideally have the new style designed for the M8. > Another factor is that the area indicated is approximate anyway and for > longer distances the lens covers more than is shown too. > You might be able to talk to a lens service agent about whether your Rokkor > mount can be adjusted or to John Milich about whether the mount can be > replaced. I would think that your cheapest option would be to just get a > new > adaptor from Cameraquest or someone similar and fit it to your CV. > Cheers > Geoff > http://www.pbase.com/hoppyman/e > http://gallery.leica-users.org/v/gh/ > > -----Original Message----- > Subject: [Leica] real focal length of M-Rokkor 2.8/28 and CV 1.9/28 mm ? > > Hi all, > > I am glad to be back on this list after a couple of years off! > > My recently acquired M8 gave me the occasion to compare the finder > brightlines to the actual field of view. > One of my lenses is a 2.8/28 M-Rokkor (originally for the CLE). On a > M6 it triggers the 35mm framelines, and on a M8 the 35 + 24 > framelines. > My other 28mm is the cosina-voigtlander 1.9/28, which I use with a > 28/90 adapter ring. > > I thought both lenses had the same actual focal length, but in fact > the Minolta-Rokkor is much wider than the CV: on the M8 it corresponds > to the 24 mm framelines. > > Does anyone have an idea of which hypothesis is the right one: > (1) the so-called M-Rokkor 28mm is actually a 24 or 25 mm > or > (2) the Rokkor 28 is really a 28, the M8 framelines are wrong and the > CV 1.9/28 is a 32mm or so? > > Anyway I am glad that the M-Rokkor mount triggers the 24 mm > framelines and I did not spend money to get a screw into the mount to > get the 28mm framelines. > > Jean > -- Jean Louchet APIS - INRIA Saclay research centre 4 rue Jacques Monod 91893 ORSAY Cedex France ---------------------------------------------------------- jean.louchet@inria.fr http://jean.louchet.free.fr/ ----------------------------------------------------------