Archived posting to the Leica Users Group, 2002/05/05
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Hi Dante, I guess the first question would be how the camera works with other lenses? I have had lenses that were "off" though it is more common for the camera to need tweaking. As you have noted, with old lenses or cameras, who knows how many times they have been repaired and by whom? The rangefinder on the M camera has two main horizontal calibration adjustments. One is the position of the roller and the other is the length of the arm. You set the position of the roller so that everything lines up at infinity and then check at 10m and 1m. The roller position adjustment is done with the eccentric screw holding the roller to the arm. The length of the arm governs the amount the shaft up to the rangefinder rotates for a given roller movement. A long arm gives less shaft rotation than a short arm for a given roller movement. The arm attaches to shaft with an eccentric pivot for the adjustment. So if you are ending up with the actual point of focus in front of the indicated focus then you need to shorten the arm to increase the rate of shaft rotation. Alas I have no advice on the lens adjustment as I have never (Did I say never? Well hardly ever.) have had M lenses apart. Good luck John Collier On Sunday, May 5, 2002, at 05:43 PM, dante@umich.edu wrote: > The specific problem is that the camera seems to line up at infinity > (focus > and RF) but at close distances focuses behind the subject (as in a few > feet > behind). > > The only thing I have been able to surmise is that either > > (a) the lens (a 50mm Nikon lens) is not collimated or otherwise is now > other > than 51.6mm FL (I did notice that the front group was screwed in a > little > past where the selected aperture matched -- probably the work of that > damn > Canon ND filter); or > > (b) the rate of change in the RF mechanism is somehow wrong. > > While I would love to believe the problem is (a) (I unscrewed and > reseated > the front group), it had no apparent effect when I did a crude > comparison of > the film-plane focus and the RF (now when the RF says on at 6 feet, you > have > to turn the lens a little more toward infinity to get the film plane to > focus). Also, the problem manifested itself with a Leica 35/2 as well. > Neither lens presented a problem on my Hexar RF. > > ??? > > I just sent it all out to be fixed today, so I guess I'll find out. > - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html