Rangefinder calibration

M

MXP

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I have observed that with my 39mm LTM lenses which fits the Fed's and Zoki's I can not just mix lenses. If I do this then when the lens is set to infinity I can't be sure that the rangefinder is spot on looking at a distant object (it as to be an antenna or something like this). Either there is to much "overlap" or to little. Is it possible to calibrate the lenses to a standard so all combinations of lens/body is possible? ......or do you have a body for each lens where you can optimized this combination to be spot on?
Does somebody understand my problem? :)

Next issue is of course that the projected image on the film shall also be spot on.
 
There's often a small difference between two lenses at infinity and it's very difficult to correct. At infinity it probably won't matter due to depth-of-field of the lens, provided the error is small. A better test it to measure 1m from the film-plane of the body and place a subject there, then see if the RF gives correct focus on the lens scale. More important still, does the RF gives correctly-focussed images?
 
I will try this with my J3. The focus has to be precise at the shorter distances especially if the lens is used wide open. The first film I got back using my 61LD on a Fed3 body I could see that the focus was a bit behind where I wanted. Then I checked the infinity focus and could see the rangefinder could not overlap at distant objects (antennas are perfect distant objects). Then I first adjusted the body to overlap and then I tested at the film plane a B-setting using a gound glass and after this at 1m and 2m. And everything was perfect.
Then I got disappointed when I put the J3 on and observed to much overlap at infinity....
 
MXP said:
......or do you have a body for each lens where you can optimized this combination to be spot on?
.
Click to expand...

I have a "preferential" lens for each RF body and I can get a good rangefinder/scale match that way; one or two lenses have a visible RF/scale mismatch with one or another body, so I do not use them together. Between both extremes, most of the combinations of LTM lenses and camera bodies give acceptable/good results to me.
Regards
Joao
 
Ok!
I also think I will go in the direction of having a matched body and lens. Many of the lenses are in the 50mm range.
 
This is a good thread; just last night I was staring at three Zorki cameras that gave me different distances when focused on the same obkect and with the same lens.

I get 4ft, 4.5ft, and 5ft.

Now I need to decide whether I send off all three cameras to a repairperson to check out the RF or whether each camera may worlk well with a specific lens.

This is not good at all.
 
Things are getting fuzzier each day in terms of figuring out whether some of my cameras has RF problems or not.
I compared the RF measures with my two Canon P cameras yesterday by using a J-8. They differed greatly from my [accurate] M6.
Today, one Canon P matched the M6 when using two Canon lenses.
 
1) Since (a) FSU and (b) Leica/Canon lenses were built to a different standard, the distance scales on (a) and (b) will show you different values if (a) and (b) are used on the same body.

2) The only problem I've encountered so far are the FED Industars (I-26M and I-61) that tend to have problems. All the Jupiters I own drive the RF identically. When I adjust body according to a J-3 and then mount I-61, it will show slightly different distances, and not always reaches infinity. In this case I rely on the extended DOF of I-61 (2.8 widest aperture)

3) RF calibration of FSU bodies is similar to FED 2, which is described here in this thread: http://www.rangefinderforum.com/forums/showthread.php?t=895
 
If one camera shows 5ft while the other shows 4.5ft is there still chance that both will result in sharp images or must at least one of the two RF be recalibrated here?
 
I have used many hours trying to calibrate rangefindes on different cameras. The real test is to set the camera to "Bulb" and aperture wide open and then use a ground glass at the film plane and then use a magnifier to be sure the sharpness is 100% at the focused distance. It is of course difficult to use a ground glass on a Fed 1 or similar types of cameras. Here it is necessary use some films to get it all right. So it is not just enough to get the "RF overlap" perfect at infinity and 1m. Leica M lenses are probably a bit more precise than FSU lenses I guess.
 
if the correct distance is 4.5 ft and you focus at 5 ft you will need to stop down to f8 to *just* get your subject in "acceptable focus," but probably you will need f11-16 to be happy with the results.

You can find the instructions on adjusting FSU RF's, but some cameras cannot be adjusted for both near and far focus using just the screw and cam adjustments.

You also want to confirm focus using film and staggered objects to confirm your lens is actually focusing where it says it is...

>>
If one camera shows 5ft while the other shows 4.5ft is there still chance that both will result in sharp images or must at least one of the two RF be recalibrated here?
 
I think 3 things has to be perfect before it is really good:

1: RF perfect at infinity and 1m.
2: Scale on lens shows the right distance.
3: Focus 100% perfect at the film then RF says so.

It should be obvious but real life often shows that it is not the case.
 
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