Fed 2 Lens Shims

[Ted Forbes]

Do the shims under the lens mounting ring on a Fed 2 serve any purpose?

Recently did a cleaning and re-leathering and was wondering if these need to be there or if I can ditch them - they are in bad shape and are a pain to get in there correctly.

thanks!

 

[Fedzilla_Bob]

From what I understand you need them, they help set the correct focusing distance.

 

[Ted Forbes]

Thanks - I went ahead and put them in...

 

[phototone]

The focus register of the camera is set by the shims. If your camera has shims, and you take them out, then when you wish to take a photo at a wide aperture, the image on the film will not be in focus at the same place as the engraving on the lens. In other words, if you set the lens to shoot a subject at a distance of 10 meters, well 10 meters will not be sharp on the negative. This is critical if you wish to shoot with normal or "long" lenses at near wide open apertures.

So, you first have to get the lens mount to film plane distance correct, then you have to adjust your RFDR on the camera to match, if you wish to have "tack" sharp photos.

 

[Ted Forbes]

Okay - cool...

So technically, I can make my own shims? I guess I can check the film plane with some vellum, a tape measure and a loupe.

Thanks guys for the information!!! The current shims are shot - torn in places and the paper is deteriorating...

 

[phototone]

You can get a reasonably priced digital micrometer from many industrial tool vendors....but, you need to add a foot to it to accurately measure depth. These feet are also available, but not normally sold with the micrometer. Without the foot you are "blowin' in the wind" as the angle you hold the micrometer at the lens mount ring will affect the depth measurement, and even a slight angle will change the reading. You will go batty without the foot.

In any case, for each position of the micrometer, you need to take several readings and average them to get a good idea of depth.

 

[ruben]

The focus register of the camera is set by the shims. If your camera has shims, and you take them out, then when you wish to take a photo at a wide aperture, the image on the film will not be in focus at the same place as the engraving on the lens. In other words, if you set the lens to shoot a subject at a distance of 10 meters, well 10 meters will not be sharp on the negative. This is critical if you wish to shoot with normal or "long" lenses at near wide open apertures..

Question: Is it possible to ACCURATELY check the focus register by opening the back of the camera and attaching any kind of glass or plastic at the film plane, which will reflect the image using a dark cloth over our head and camera) and then inspect the reflected image with a magnifying glass ?

Thanks in advance,

Ruben

 

[Ted Forbes]

Thanks SOOO much - this is a big lifesaver with me being an amateur repair man at best!

Tell you what - I'm going to make templates for the shims and the leatherette - I'll post them for download when I'm done.

That's what you guys get for being so helpful!

A friend of mine went home to Russia last spring and brought be this FED 2 as a gift. He bought it for $5 at a flea market - appearently they are loaded with cheap rangefinders. Well - this one worked great except for some holes in the shutter curtain, a lot of grime on the knobs and the vulcanized finish was discolored.

I ran a test roll and the thing took some great shots save for the light leaks. I photoshoped them out and decided to make this my project camera.

I repaired the shutter with a liquid rubber compound and it seems to have done the trick. Now I'm messing with the rest of the camera.

By the way, this was from the test roll.

Not a great shot, but you can see the color is good and the lens is sharp!

http://www.rangefinderforum.com/photopost/showphoto.php?photo=14774&cat=500&page=1

What a great community here! You guys have been a tremendous help. I was a little timid about posting at first since I don't own a Leica or any thing else over the $100 mark! Glad to see people interested in all kinds of Rangefinders...

 

[Kim Coxon]

Hi,
You can also get a set of 14 shims from Aki on eBay for $7. For some reason he sells them from his eBay shop but they are not listed on his website. This goes for some of his camera coverings as well. If you email him, you can normally get them direct.

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=7531977479&rd=1&sspagename=STRK:MEWA:IT&rd=1

Regards
Kim

 

[Mike Kovacs]

The shims need to be replaced in the same holes that you took them from. They are not necessarily the same size. I have shimmed a Contax II with a depth gauge and its slow, methodical work to get it right. You have to get it right to about 1/1000" of an inch. Once done, I checked the centre and four corners of the frame with my collimator. I've since added a 135/4 lens and it focuses flat.

If you read the Kiev Survival Site, he gives a supplier of handy brass shims from a model railroad store that are about the correct size for camera work.

The good news for you is that at least the M39 mount is flat on the outside. It'll be easier than a Contax bayonet mount. You will need something flat and hard like a piece of glass to put in the film gate to sit on the inner rails. Measuring off the pressure plate is no good because it moves as the gauge touches it. Leica screw requires a film to flange distance of 27.80 mm. (1.094")

 

[pshinkaw]

The tolerance range for the film-plane to flange diustance on an LTM camera is 28.78 to 28.82 mm.

I made a template from an old credit card in order to simplify the cutting. A leather shop like Tandy Leather can supply a mini-punch set which will allow you to cut the proper size holes for the screws. Different kinds of materials will supply shims of varying thickness. Examples are 12 lb printer paper, 20 lb printer paper, peel off label backing paper, etc. I have found it easier to to use muiltiple thin shims rather than a single thick one. Also, some of the materials will compress when they are actually placed under the lens mount. Thus, you may have to go slioghtly thick in order to allow for compression when the screws are tightened.

I have achieved my best results from just going for the middle of the tolerance range rather than trying to check focus with a viewing glass and rangefinder. However, if you eyesight is pretty good, the "focus check" method may work better for you than it does for me.

-Paul

 

[laptoprob]

I I have to check focus on any camera I take a SLR focusing screen with split-image center. I have a X700 with a focus problem so it serves as a donor for this screen.
By taping the screen on the film plane you can check the focus easily. If necessary with a loupe.
Remember to use the correct side of the screen!

Rob.

 

[Kim Coxon]

Hi,
I use a spare matt screen from an LX. I managed to scratch it and replaced it but it is good for this kind of thing. One thing to remember is to use a known good lens preferably with a wide aperture. Many of the FSU lenses are slightly out. This will work fine if you are mating a particular lens to a body but can play havoc otherwise. For this reason, I use a CV 50/1.5 Nocton to check FSU bodies and the Bessa R body the check FSU lenses.

If you need to do several FSU cameras, it is worth picking up a cheap parts body. For the Fed 2s, I have a back with a hole cut in it so I can mount the camera on a tripod to set everything up and am just about to chop a Zorki 4 back. (No problem with the Bessa as it has a hinged back)

As a matter of interest, I have now received at least 3 cameras from "over there" that have had no spacers or at had odd pieces in. It is well worth checking. Not a problem with cameras from the likes of Oleg but many of the dealers on "that" place, would appear to know not very much about cameras and are merely passing them on. With very few exceptions, all of the lens I have had, have needed at least a re-lube and have also benefitts from a minor adjustment to the collimation.

Kim