Hi Stef,
I am going to propose you a method based on the KSS, but altered by me. It will not spare you from opening the top casting, but after that it may spare time and desperation.
The logic of my alteration is the following. We have 4 elements adjusting the yellow patch coincidence and we will intruduce
a strict division of labour for them.
One of the four, it seems to me is not mentioned at the KSS, and if it is i strongly appologize to Russ. It consists in the possibility of lateral displacement of the front square glass element, used too to adjust the vertical coincidence, but in our case the vertical issue is of no importance, unless we have a problem there too, which is unusual. We will use this square for lateral displacement too.
The possibility of this lateral displacement is built in in the fact that the holes of the square glass metal frame, are considerably bigger than the holes at the place where its screws sould be inserted.
Of course I take for granted you have removed the top casting and uncovered the long black prism.
So my logics is the following. With the "worm" arm and the screw regulating its angle of displacement (see the screw at utmost right side of first pic at
http://www3.telus.net/public/rpnchbck/adjust rangefinder.html) and with the arm there bearing number 4 - we will calibrate the short distances. It will be done in a certain way that i will explain later below.
With both glass pieces, the plano convex and the plano concave, numbered at that pic as 1 and 2 - we will calibrate infinity.
This will be our
division of labour and we will stick to it to death, as not to go crazy. (We will prefer to be dead and not crazy)
We will adjust the short distances coincidence first, and then the infinity afterwards. This is very important because with a good short distance coincidence first, we will arrive at a less problematic coincidence at infinity, while the contrary is not necessarily as profitable. As you know, there is much more helical displacement at the short distance than at the infinity and surroundings.
However, before we adjust the short distance, we will bring the two glasses we destinate for infinity adjustment, into some kind of "neutral" or average position. This will leave our chances of displacement open for both directions.
Now, what to do, how, and in which order.
The one meter adjustment
Here we will start by centering the convex and concave glasses to dead center position.
a) Go again to the same link of the kss, and start counting until you see pic number 8. Unscrew all 4 screws and take out the square piece.
b) Invert the whole camera, so that you can have a good view of the four egg shaped holes of the camera body, designed to adjust the concave and convex glasses.
Clean this part if it is dirty, to obtain maximum clarity. Then mark with a sharp tool the center of each hole, in order to let you realign the four screws at dead center.
c) In a few moments you will be going to re install the concave and convex glasses aligned by the screws placed in their center position. Note that at the small square glass you will have some play to lateral displacement, that we will take advantage of, but by now we align and screw everything at dead center.
All 4 screws should be adjusted strongly.
d) But in order to help yourself, before reintallation of glasses, remove the selftimer lever, as it stands in your way for a straight screwdriver operation.
e) Once you have installed the main compensator including the rectangular glass, this is the best time for you to clean this glass in the best possible way. The most common error when cleaning this glass is to apply too much liquid cleaning. Home alcohol or Isopropyl alcohol are ok, but use very very tiny ammounts.
f) Before reinstalling the square glass, clean it too, re-install it, and re-install both the metal housing serving to sustain the outer glass. Install this glass to using any kind of masking tape, just to protect the cleaning you have performed on the square glass. Latter, when you close your camera with the front plate, you will remove this masking tape.
By now, it is the best moment too to clean the 4 glass surfaces of the black long prism. These surfaces are the most delicate of all, but we shouldn't be hysteric here too. If our cotton tip with which we have wet cleaned previous glasses is amost dry, this is the best for cleaning the prism glass surfaces. Another good method for these surfaces is to use soft toilet paper, sustained by our cotton tip for long circular and soft frictions.
Finnally, on the cleaning, we should clean the square internal glass face of the eyepiece, that face facing the prism. The outer circular glass face of the eye piece will be cleaned several times along our arrangements, since it is the most prong to get greasy, and finally before we close the top casting.
Bacj at our present alignment stage, what we have done is to align our plano convex and plano concave lenses at "average" center position, so to start aligning the other parts with a good start. Let's go now for the other parts.
g) Go again to the same link and start counting from top until you reach pic number 20.
h) Bring the worm, through actioning the small wheel to 1mm from the edge. This 1mm is to be measured by bare eye, but looking from above, without any lateral eye deviation.
i) Place an SLR
split image screen at the film plane, camera on tripod, and a standard lens on your camera. Have your subject for metering close distances place at an accurate 1 meter from film plane, either by moving the subjec or your tripod.
Then with another 50mm lens of any kind, look through the
split image screen at the film plane and adjust camera wheel for sharpness. By this we will obtain film plane accuracy. 1 meter subject is sharply reproduced at our film. Notice I am not speaking about distance scale of our camera, on purpose, upon Rick Oleson advice. But I am speaking about a split image screen, i,e, that one with an horizontal or diagonal line at center, as according to my observation the level of accuracy you gain from the split image is unsurpassed by far and large with any other substitute, but for a single exception.
This single exception comes from the SLR manual focus golden age, in which some trendy folks get used to an uncluttered clean matted type of screen, without any focusing aide at its center, annoying their photographically correct frame view. If you have been a champ of these acrobatics, with duplicated certificates in the form of your enlargements, then you may feel released from the split image screen. Otherwise you will see by yourself that any non split image substitute will leave an exaggerated range of distances being seen as 'sharp'.
j) Now, our task will be to bring range finder coincidence to match screen at film plane coicidence. For this task we will use exclusively the screw at the first pic of the quoted link, the screw at the extreme right. This screw is strongly tightened and once we achieve coincidence we will re-tighten it at maximum hand force (of course that if you are a box champ, you will use your common sense)
So by now whe have sharp rf and film plane coincidence for short distances. Eureka !
Eureka, because what is left is much much easier.
Adjusting for infinity.
a) camera on tripod,
split image screen at film plane, we will play ONLY with those four screws of the plano convex and plano concave glases. But there is an order here too.
b) bring camera on tripod to the place you view a long distance subject serving you for infinity. and bring you focusing wheel to infinity. First we have to deal with the reality, i, e, the image at the film plane, i.e, the screen split image you put there should indicate infinity.
d) For the final yellow patch coincidence of infinity you will use
first the lateral displacement of the square plano concave glass. Loosen them and find the direction of displacement you need. It may happen that after finding the direction you need, and mooving the piece in the whole extent of that direction, it will not be enough to have yellow patch coincidence.
In this case you will further help yourself by displacing the rectangular glass.
After you finish with vf infinity coincidence, go back to check both coincidences for short distances, i,e, film plane split image and yellow patch. They should be ok, unaltered by infinity adjustments as performed this way.
Cheers,
Ruben
