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Trying to understand rangefinder misalignment


chris_tribble

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Thanks to all who've commented on this instructive thread. I'll be sending the M9 in for a bit of TLC as it's in warranty - makes sense to have things as good as you can get them - though you can see from the attached, that the body is actually having no problems focusing at infinity (EXIF data = 50 lux @ f5.7 / 1/1500)

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...Closeup is most critical and easily noticed, but the infinity focussing in the RF will show up at the smallest twist of the focusing ring. Even if it is off minimally, as long as the lens focuses to infinity you wouldn't notice. So in your case it is probably just the infinity linkage that is slightly off. That means that if you were to correct it by the Allen key method, you would most likely throw close focus out...

 

Apologies if I've obscured the interesting points in this post.

 

Considering the amount the lens moves and the rotation of the rangefinder "mirror" as functions of the distance, the linkage between them is nonlinear. (Linkage including the lens mount cam.)

 

What I don't understand, after reading the service manual, is the actual effect of the two adjustments...like whether the error of a misadjusted rangefinder is linear with the distance. I guess it's not. If it is, you could measure the error at two distances and know the compensation for every distance.

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  • 11 months later...

The special tool to adjust horizontal misalignments is available on ebay from Mr.Zhou. I have made it

myself from a screwdriver. You need different ones for older M´s from M4-M6 and MP bodies. Those bodies

that have the Red dot can all beeing adjusted with the same tool, like the one from Mr.Zhou. The MP has

the traditional M3 screw but inside the adjustment is different from the M3 and the cutout is to small to allow

the M6 tool in.

 

Basically it´s possible to adjust DIY, it´s just a question of how patient you are and how long you can

stand the try and error process.

 

Shimming lenses is another story beause if you start doing this you will disturb the rangefindern cam of

the lens as well. It is possible, I speak from experience, but there is always a risk.

 

If you can get one of Ed Rommney´s repair books read this, the Tomosy book is good but explains the whole

thing "only a little bit".

 

Jo

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...

If you can get one of Ed Rommney´s repair books read this, the Tomosy book is good but explains the whole

thing "only a little bit".

 

Jo

 

Can you give the titles of these two books...

 

Thanks

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Okay so what about when its the lens that is off at infinity? Lars and Jaap- and others- can you explain what is going on with my 50 lux ASPH:

 

It focuses fine up close but at "faraway" infinity- let's say a kilometer or more away- there is a double pole when I focus on a light pole on a bridge (for example). At 0.5 km "infinity" seems to be spot on (no double pole). The "faraway" infinity image itself seems to be just fine when I zoom in on the LCD screen. The rangefinder seems to not go quite far enough resulting in the "double pole" effect- rather than overshooting.

 

This problem does not exist with numerous other lenses including a 75mm and 90mm lens. I also get essentially the same results with the M8.2 as I do with the M9- in every respect and with various lenses.

 

I think (and hope) this is more of an annoyance rather than a problem that results in poor IQ. What do the experts on the forum think? Thanks.

 

I have 2x 50 asph lux and both exhibit exactly the same feature of lack of rangefinder coincidence at infinity. One is miles off and images at infinity and close are not accurately focussed. The second is spot on at infinity and 1-2m...... but seems wayward at 5m or so. I also am very perplexed by this lens. Most of my others, including the ones where problems are obvious: 135, 90/4, 50/2 are all perfect. The only other 2 (of 13) which are iffy are my 75/2 which is way off and my 90/2 which is ok at infinity and 2m+ but useless at distances closer than that.... which is another mystery.....

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And then, send your camera and your holiday fund to Leica in order to have the rangefinder readjusted so that it works again. :eek:

Seriously though, although the basic adjustments are quite simple processes. If you try to do this without the correct test jig, and technical proficiency in such adjustments, you stand a very good chance of mucking it up completely.

 

yes...... but Leica do not calibrate to real infinity....... unless they have a tower with a window lined up on some electric pylon 5km away and decent weather every day.

 

that's probably why nothing ever comes back perfect first time........ particularly lenses.

 

I have to agree with Julian that self adjustment of the camera .....IF YOU HAVE A LENS THAT IS PERFECT...... is probably better and quicker than Solms can manage.

 

The problem is sorting out how much of the problem is lens based and how much is rangefinder adjustment based....... and of course lens adjustment seems to be a black art that we are not privy to.....

 

Calibration is done to a RANGE..... not a fixed point, so getting a camera and half a dozen lenses to all work PERFECTLY together is a tall older. Luckily with anything under 50 there is a lot of leeway, but very fast complicated lenses like the 50 asph lux used wide open are very intolerant of any miscalibration.

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And then, send your camera and your holiday fund to Leica in order to have the rangefinder readjusted so that it works again. :eek:

Seriously though, although the basic adjustments are quite simple processes. If you try to do this without the correct test jig, and technical proficiency in such adjustments, you stand a very good chance of mucking it up completely.

Hi there!!:):):) Where have you been?
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yes...... but Leica do not calibrate to real infinity....... unless they have a tower with a window lined up on some electric pylon 5km away and decent weather every day.

 

that's probably why nothing ever comes back perfect first time........ particularly lenses.

They can use infinity with a reference collimator.

 

I have to agree with Julian that self adjustment of the camera .....IF YOU HAVE A LENS THAT IS PERFECT...... is probably better and quicker than Solms can manage.

all the lenses will be to a production tolerance not perfect, unless they have been damaged or stipped & reassembed by previous owners... you are about to damage your kit deliberatly

The problem is sorting out how much of the problem is lens based and how much is rangefinder adjustment based....... and of course lens adjustment seems to be a black art that we are not privy to.....

it is difficult enough getting the mount to registration distance near correct...

You need to get the lens focal length close to the heliciod pitch/movement, and the lens stand off distance close to correct, two shims replacing... should be ok first time with a sphisticated optical bench. A floating element might need a third (or forth) shim.

... Luckily with anything under 50 there is a lot of leeway, but very fast complicated lenses like the 50 asph lux used wide open are very intolerant of any miscalibration.

The shorter lenses have more depth of field but are still critical on depth of focus. Lots of problems with the 35mm lux...

This is not something new the Noct f/1 in '78 was creating problems, lots of people needed to send in their film M bodies, when they bought a Noct...

 

Noel

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This is not something new the Noct f/1 in '78 was creating problems, lots of people needed to send in their film M bodies, when they bought a Noct...

 

Noel

And they put their other lenses into the bin?

Jan

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They can use infinity with a reference collimator.

 

all the lenses will be to a production tolerance not perfect, unless they have been damaged or stipped & reassembed by previous owners... you are about to damage your kit deliberatly

 

Noel

 

???

 

Then why do so many people have to repeatedly send cameras/lenses (or both) before they are satisfied ???

 

Adjustment is not 'damage'.

 

All the camera rangefinder adjustments (except the mid range metal bending one with the mysterious tool Jaap alluded to on another thread) are well within the capabilities of most Leica users ..... you just need the right tools, care and a logical mind.

 

If Solms turned around things quicker it wouldn't be an issue......;)

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And lens adjustrment is not a Solms monopoly - I sent my Apo-Telyt in for coding last Friday to Will van Manen and asked to check/adjust the focus at the same time - It is in the mail on its way back to me as I type - well within a week....I imagine other reputable Leica repair shops work in a similar way.

 

 

If Solms turned around things quicker it wouldn't be an issue......;)
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???

 

Then why do so many people have to repeatedly send cameras/lenses (or both) before they are satisfied ???

I do not know but a high precision infinity is possible on a jig. I think that Leica may have revised the nominal standard and decreased the tolerances.

But that does not account for Andy's MP rfdr problems which were either quality control or damage in transport.

Adjustment is not 'damage'.

If is if you set your equipment up so that it works but if you sell it is not to the production criteria. Kiev's were made like that...

All the camera rangefinder adjustments (except the mid range metal bending one with the mysterious tool Jaap alluded to on another thread) are well within the capabilities of most Leica users ..... you just need the right tools, care and a logical mind.

 

If Solms turned around things quicker it wouldn't be an issue......;)

I suggest you need an optical collimator to adjust the sensor to mount register, and you need to know Leicas nominal standard and which bit (depth) of the image they reference on, two unknowns...

I was not aware of the metal bending tool, I'm suprised, the eccentric mount should not require the arm to be altered... Unless the rangefinder has been simplified from the M2 and M3 I use...

Do you know what Leica set the body parameters to? If you do when did they change these last?

If you need to adjust a lens it is difficult without an awareness of the lens design, where the lens is in the production variation set and a set of adjustement shims.

The Kiev equipment is difficult to work with as Zeiss had strange ideas about tolerances, all the plans were destroyed in a USAF fire storm and the FSU factory and kitchen table maintenance had different game plans.

Unless you have current information from Leica, I'd suggest you dont have an option. And this was something you should have been aware of when you got your M9?

I accept that having to post the camera to black forest is well inconvenient, as in the past the Leitz maintenance shop was only ever a few blocks away, and they sometmes provided a while you wait over the counter turn around, even for a lens mount swap. But that was yesterday(, well 1970 then). Leicas seemed more reliable then.

 

Noel

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Noel.......

 

I am just about mad enough to tinker with the simple rangefinder adjustments....:p

 

I will leave lenses to braver inveterate tinkerers to the like of Washington...... :D

 

On this issue I think I will adopt Julians approach and just shut up and get on with it.

 

Any confession that you 'interfere' with your Leica is viewed by some members as a form of socially unacceptable camera abuse.....

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The original question re non-alignment of far objects is something I have also noticed on my M7. This was bought new in late February and for months I only used in urban environments, mostly for 'street' subjects. It was only when on holiday in June that I noticed that distant objects such as poles were not fully aligned - when turning the lens to infinity, the split image stops just short of alignment. This was common with my 21, 35, 50 & 75mm lenses. (I just took delivery of a 1969 Summaron 35mm this week - same situation). However, as the images show no misalignment of distant objects and focus looks fine throughout, I was tending to ignore the 'problem'. Now reading this thread, I wonder if I would be advised to send it in whilst it is still under warranty? The image below is from a test roll with my 'new' Summaron. Your thoughts would be appreciated.

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