FED2 - DIY VF/RF Service (long w/images)

RML said:
I'm wondering what makes a VF bright or not. Why are the Bessa and Leica VFs so much brighter than the FED's? Obviously the size of the window ill have something to do with it, but what else? Would resilvering the mirror or using clearer glass make a difference? I'm thinking that it shouldn't be too difficult to make the FED's VF at least a bit brighter than it is now....
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VF/RF brightness relates partly to the quality of the components, and also to the design of the rangefinder optics.

In a combined VF/RF, the rangefinder image has to be "inserted" into the viewfinder image path. To make this work in the usual coincident-image design, there needs to be a semi-reflecting mirror (aka beamsplitter) in the path, so that both the viewfinder and rangefinder images can be combined together.

The inexpensive way to do this is to have the semi-reflecting mirror cover the entire finder area; that's how they do it on a Fed (and most other RF cameras that have a rangefinder patch with blurry edges.) This reduces overall finder brightness, because the part of the viewfinder outside the RF patch is also only semi-transparent, and doesn't pass all the light.

A more expensive and elaborate way of doing this is seen on some Canon and Nikon RF cameras. In these, the beamsplitter was masked before the reflecting material was coated onto it, so that it's ONLY semi-reflecting in roughly the area of the RF patch. (Looking at the beamsplitter from the front, often you can see vertical and horizontal 'gunsight' marks left by the wires that supported the mask.)

This allows the rest of the finder area to be brighter. The downside is that since the beamsplitter, RF image, and viewfinder image are focused at different distances, the RF patch not only has a blurry edge, but often a dark halo around it (from the unsilvered area of the beamsplitter.)

The best but really expensive way to do it, as used on Leicas starting with the M3 as well as on the Minolta CLE and the Bessas, is to use a complex optical system inside the RF/VF module. This incorporates a system of lenses and prisms that allow the designer to achieve focus of the viewfinder image, the framelines, the rangefinder image, and the edges of the rangefinder mask, all at the same point. This gives a sharp-edged rangefinder patch and also allows the semi-transparent area of the beamsplitter to affect ONLY the patch. This allows full brightness for the rest of the focusing area. (Actually the rest of the area must still be somewhat semi-transparent, so that the framellines can be reflected into it, but the brightness loss is not as great.)

Take a look at a diagram of a Leica or Bessa RF/VF module, and you'll see how complex it is. That's one reason a modern RF camera is so much more expensive than a similarly-featured SLR!


As to trying to make the finder image brighter in a Fed or similar camera: You probably don't want to do it! You could certainly brighten the image by polishing off some of the semi-reflecting material from the beamsplitter. But that would make the rangefinder patch harder to see, because there would be less material to reflect it into the finder view.

Your best bet probably is simply to make sure that the optical surfaces inside the finder are as clean as possible. Use great care if you decide to clean the beamsplitter itself, because the semi-reflecting coating rests on the glass surface and is easy to remove by accident.
 
C-Petteri said:
I also would like to know if Zorki cameras are similiar from inside ? I have a Zorki 1, which rangefinder needs some tuning (distances just don´t match), but I don´t know if I have to remove the top plate to fix that problem or not. Any help ?

I also have a Moskva 2 camera which has a similiar problem, but that´s a different story, I think...
Click to expand...


nice to "see" ya here, Petteri!
 
Thanks a lot~!It was very useful for me~!
But my fed-2 seem some problem now.
It will sound "sqeeze" when I push the shutter release.
Don't know what happen on it.
But when I push Harder or the shutter speed more lower.
The sound will disappear.
Can Any one help me about this question.
Thanks alot
 
Probably it would need a bit of lubrication - I have one FED 2 that also makes squeaking noises at 1/100 and 1/250, but not at other speeds, and my other FED 2 is really silent (but that one was CLA'd by Oleg...)

Roman
 
Thank you Roman
I will send it to my other photomate for a certain check.
Who knows what happen next with FSU-made Fed-2.
But I will very sad now......
 
Originally Posted by C-Petteri
I also would like to know if Zorki cameras are similiar from inside ? I have a Zorki 1, which rangefinder needs some tuning (distances just don´t match), but I don´t know if I have to remove the top plate to fix that problem or not. Any help ?

I also have a Moskva 2 camera which has a similiar problem, but that´s a different story, I think...


Zorki and FED 1 adjustments are the same, as far as aligning the rangfinder spot.

http://home.att.net/~wayne.cornell/camera/repair.htm
 
I removed the screw, the winder itself seemed to be locked in..

I mean yes i can't unscrew the knob..
 
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Work was on halt yesterday, i found out that there's missing gear...It was sunday shops were close..I'll resume today. But the lens screws are irritating..
It's awfull being new on the job :D
 
All is back together now, everything is in place...And working.

It feels much better now...It also feeels good to be that familiar with ur camera.
 
I was seduced last night by a black FED 2 from the baying auction house. I hope that it is quicker than the last shipment from the FSU, otherwise it will get caught up in the Christmas postal mess. It's comforting to know that there is so much intellectual knowledge around on this camera, which I must admit has considerable appeal. The photo on e-bay shows the serial no as being 315685. On the assumption that this is correct, and to date I have no reason to belief otherwise, is there any way of finding out what year it was produced?
 
No, the SN on a Fed has no discernable relationship to the year of manufacture. If the lens is original equipment that might give you a clue, or maybe not. On a Fed-2, the best you can do is to identify the sub-model based on the features and then research the time span when that particular sub-model was in production. Parts are easily interchangeable on Fed's and the Soviets practiced incremental product development so even that can be uncertain.

-Paul
 
Thanks - I noted the earlier reference to model variants in Laika's post. I'll wait until I get it in my hot sticky hands.
 
hello
in respose to which russian rangefinder , for me the zorki 6 fits the bill, i have tried a zorki 4 and it way cool but messing around with the removable back and the loose spool just got to be problematic. If you can get your hand on the Olympus rc35 rangefinder go for it because its all time favorite compact street shooter. Russian Lens are wow for the price jupiter 8 nice, happy clicking

jerry
 
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