Maintenance and repair
of a Nikkor telelens for Nikon rangefinder cameras
In the old days of photography most photographers had three lenses in their bag: a standard lens with a focal length of or around 50 mm., a wide-angle lens with a focal length of 35 mm. and a telelens with a focal length of 85, 105 or 135 mm.
To clean or repair a Nikkor telelens - used on Nikon rangefinder cameras - isn't a difficult job. As an example the Nikkor 3.5/13.5 cm. will be the victim lens in this chapter.
Like the 13.5 cm. lens shown above, the 8.5cm and the 10.5cm have a more or less identical body.
It is relatively easy to open the lens. Just take the front and the rear with your both hands and screw off the front part (with a long thread) CCW.
The bottom part/barrel of the lens is just a metal tube with the lens mount, tripod connector and helical focusing mechanism. No lenses at all! If focusing is stiff you can lubricate (a few drops only) the helical unit from the back inside.
In order to get to the diaphragm blades unscrew the front part of the lens by holding the rear part in your left hand and unscrew the front part of the lens body (above the diaphragm indicators) CCW with you right hand.
Here you see the front lens elements separated from the front lens body
If you want to remove the front lens element you should unscrew the black retaining ring (with all lens engravings). In between 'cm' and 'Nippon' and on the opposite side just to the right of the serial number you'll see two tiny holes. With a pair of pointed pliers you may unscrew the ring CCW.
In the lower part of the front lens body you'll find the diaphragm blades. The blades can be cleaned from this side. If you want to get the blades removed, you have to remove the C-spring first.