How to adjust the rangefinder on a Kodak Retina IIa
Most often you will need to remove
the r/f in order to clean and lubricate the pivot point. The rangefinder itself
is held to the camera body by two screws at the bottom of the holes indicated
in the picture below. If you are happy that the mechanism is not sticky
from dried out lubricants you can skip this bit and just
move onto the infinity position adjustment in the third picture.
In the picture below you can see the rangefinder turned over to show the spring that returns the movement to the infinity position D and the pivot point for the moving arm E. You will often find that the pivot is gummed up with old lubricant, or perhaps some corrosion, dust or sand, and the moving arm is not pulled back to the infinity position by the spring consistently.
Unhook the spring, taking care not to loose that silver pin at D. Unscrew the pivot screw at E and note the position of the large diameter narrow wavy spring washer which is fitted between the moving arm and the heavy black washer directly under the pivot screw. The arm pivots around a brass bush loosly fitted in the arm. Be careful not to loose it.
Clean all surfaces
and lubricate sparingly with your favourite light lubricant. A little graphite
can work well for this job, but don't blow graphite powder into the rangefinder
itself. Reassemble and check that the moving arm returns to the rest position
smoothly under the spring tension by itself.
Here you see the rangefinder removed from the body for clarity. To make your adjustments you will need to fit the rangefinder back onto the camera body. Note that the tip of the moving arm on the rangefinder should be in front of the screw connected to the focus adjustment. As the focus is turned towards the infinity position this screw moves towards the back of the camera allowing the moving arm to be drawn back by the spring. Moving the focus towards a closer distance pulls the rangefinder arm forward against the return spring.
For normal horizontal adjustment of the image at the infinity position you will need to slightly loosen the lock screw labelled B in the picture below, turning the larger screw head labelled C one way of the other to bring the images of a suitable distant target into alignment while the camera lens is set at the infinity position.
When you are happy with the setting lock it with the lock screw B and recheck. (See below for adjustment for vertical alignment of the rangefinder images if needed)
If the rangefinder images are out
of vertical alignment then you will need to adjust the angle of the prism visible
here. Note that the adjustments needed are very slight, just a fraction of a
turn of the screwdriver will make a large difference in the image position.
If the moving image in the finder is too high you will need to slacken the screw at G and tighten the screw at F.
If the moving image is too low, then slacken the screw at F and tighten the screw at G .
You only need to make very small changes in the adjustment to make large changes in the image position, so go carefully!