Super Ikonta 531/2 - Rangefinder adjustment

[Thomas78]

Hello,

due to a non working shutter I had to disassable the lens of my Super Ikonta 531/2.
Fortunately the problem was just some lube/resin which glued up the shutter blades.

After some cleaning I was able to reassemble it and both the fast and slow times seem to work fine.

But while dissassembling the two prisms of the rangefinder fell out of the place.

I tried to put them back in the right position so that the superimposed image moves horzontal with the help of Dante Stellas website:

http://www.dantestella.com/technical/superfix.html


Now the image moves horizontal, but I have some problems with the calibration:

When I calibrate the RF to infinity, and then look at minimum distance, the RF (the scale at the lens) says 1.5 m when it is about 1.6 m in reality.
There is also some small slack in the gearing:
I can move the lens about +/- 1 mm at its rime while the prims does not move.


Do you have any idea what might have gone wrong?
(As far as I know, the rangefinder was working before the dismanteling.)


Regards,
Thomas

 

[Thomas78]

Perhaps I am just to critical.

Today I cross checked the 531/2 with my 530/2 and my Moskwa 5.

First I checked all at infinity: All three were spot on.

Then I measured an object in 2 m distance with the rangefinders.

The 530/2 : almost spot on (somewhere between 1.95 - 2 m)
The 531/1 : about 1.90 m
The Moskwa 5: about 2.10 - 2.15


At closer distance the accuracy of the rangefinder seems to fall a bit off:

The Moskwa 5 indicates 1.60 m at 1.50 m and 1.85 at 1.70 m.
The 531/2 indicates 1.60 m at 1.70 m.

As the Moskwa shows about the same deviation (but in the different direction) this might be within the product tolerances. The deviation is about the DOF indicated for f/4.

When using your folder at f/8 or f/11 this would not matter for shure...

 

[literiter]

I would use a ground glass on the focal plane and check focus with a loupe.

Getting the adjustment can be a little fiddly but much easier on the 531/2 than say the Super Ikonta B, 532/16.

 

[Thomas78]

Paul,

I checked the focus with an improvised ground glass (parchment paper - my 6x9 ground glass with frame does not fit the camera).
After putting the front element in place at the right position - it has a tree thread helix - it is now spot on at f/8 but seem st show some front focusing at f/4.5.

As an additional check I took some images with the scale at 1.50m distance and newspaper cutouts from 1.30 - 1.70. But it will take some time until I can develop the film.