Jump to content

DIY lens adjustment


rapids41

Recommended Posts

Advertisement (gone after registration)

Hi,

 

I am just familiar to adjust the RF on my M9, but still not all my lenses focusing correct at all distances.

So the next step will be to adjust the lenses. This should not be difficult in theory, just put the ring where the roller slides a little back or front.

Another way will be to rasp the ring or to stick something on it?

Does anyone here have done this or knows how this will work?

 

Please dont say sent it to Leica or another repair shop.

 

Michael

Link to post
Share on other sites

I sticked a strip of scotch on the cam of my 135 2,8 and, by chance, it proved a good solution for a slight misadjustement.... but is better not to go further with experiments....:cool:... a trustable repair shop, or Leica itself, is surely better than embarking in risky mechanical (or , worst, filing) jobs.

Link to post
Share on other sites

I've been pondering on the same ......... obviously some of the complex lenses with floating elements must be difficult to adjust ...... but getting the simpler ones just corrected for infinity can't be impossible ......

 

Try as I might I cannot find any manuals or general instructions ..... so it looks like I will be buying some junk off eBay to dismember and work out how it is done........

 

..... collimating is not that complicated ........ surely ......... :o

Link to post
Share on other sites

You need a collection of internal shims down to 0.01 mm for the lens. If you don’t have them you will be doing a butcher’s job. With the M240 (EVF) a collimator is not needed.

Edited by jaapv
  • Like 1
Link to post
Share on other sites

Hi,

 

Another way will be to rasp the ring or to stick something on it?

Does anyone here have done this or knows how this will work?

 

Michael

 

Michael, please, don't!

 

If your lens is focusing different at different distance, you messed up the lever of the RF.

 

To adjust a lens requires more than some mechanical skills.

You need a deep understanding of the design of the focusing assembly.

 

Send everything to a trusted repair shop or to Leica.

 

Franco

Link to post
Share on other sites

Advertisement (gone after registration)

If you search in the forum you will find a very clear description of the adjustment of the lever.

You can (I) change the angle of the lever, which changes the alignment of the finder at all distances and (II) change the length of the lever, which correct the misalignment of the finder at different distances.

 

I try to give you a clue about a rangefinder lens.

 

During the years, Leica changed many different designs, but basically all lenses are made of two sub-assemblies: the focusing SA and the optical SA.

 

There are some exceptions to the rule (eg Elmar m 50) but in most cases the SAs are joint together with some shims in between to adjust the length to the lens.

 

The right way is to first adjust the focusing SA. This is done in many different ways, depending on the, lens. In example, a Summarit 2,5 50 has three screws to change the rotation of the helicoid. It's a very very well designed lens, but this is a different story. Other lenses are more difficult to adjust, but the only thing you MUST refrain from is to grind the part were the RF lever touch.

 

The focusing SA is never adjusted on a camera, to make a good job, a test bench is required. If you set your lenses on your camera, you compensate for the tolerances of your camera. This is not a good idea. Just believe.

 

After the focusing SA is adjusted at the perfect length for infinite (not for closer distance), the optical SA is attached and checked to focus perfectly.

 

This is done adding thin shims between the two SAs.

The tolerance is very tight. We are talking about hundreds of a mm.

 

as you see, this is not a DIY job.

 

Back to your problem: have the lever of the RF adjusted and all your lenses will focus consistently at all distances. Which is: if a lens back focus at short distance will do the same at longer ones.

This being the case, some shims are required within the two SA

 

If a lens is perfect will focus spot on at all distances.

 

I hope this will make you pick up the phone and call a trusted shop or the excellent (but not cheap) Leica customer service.

 

Ciao

Franco

  • Like 2
  • Thanks 1
Link to post
Share on other sites

Michael,

 

You own a precision, high quality camera and lenses with, no doubt, a substantial investment, and you’re thinking of futzing about by adjusting the focussing mechanisms by ‘rasp[ing] the ring or to stick something on it’?

 

Each to their own. Personally I think you should sit down, take a calm, considered breath, and have a reality check.

 

Honestly. Words fail me.

  • Like 1
Link to post
Share on other sites

If you search in the forum you will find a very clear description of the adjustment of the lever.

You can (I) change the angle of the lever, which changes the alignment of the finder at all distances and (II) change the length of the lever, which correct the misalignment of the finder at different distances.

 

My rangefinder is already adjustet to my 50 SLX ASPH, which is spot on at all distances now. I think thats the best way because it has the least DOF of all my lenses.

 

I try to give you a clue about a rangefinder lens.

 

During the years, Leica changed many different designs, but basically all lenses are made of two sub-assemblies: the focusing SA and the optical SA.

 

Are that the two units in this video for which the pipe is needed?

 

There are some exceptions to the rule (eg Elmar m 50) but in most cases the SAs are joint together with some shims in between to adjust the length to the lens.

 

That sounds interesting. So if I have backfocus at all distances all I have to do is to remove some shims?

 

Other lenses are more difficult to adjust, but the only thing you MUST refrain from is to grind the part were the RF lever touch.

 

Ok ok, I think thats realy a bad idea. You got me. :D

 

The focusing SA is never adjusted on a camera, to make a good job, a test bench is required. If you set your lenses on your camera, you compensate for the tolerances of your camera. This is not a good idea. Just believe.

 

Why? If the lens is ok and I adjust the RF of the camera to that lense, all should be ok!?

 

After the focusing SA is adjusted at the perfect length for infinite (not for closer distance), the optical SA is attached and checked to focus perfectly.

 

This is done adding thin shims between the two SAs.

The tolerance is very tight. We are talking about hundreds of a mm.

 

as you see, this is not a DIY job.

 

Ok to adjust the optical SA not, but to add or remove some shims between shouldnt be so difficult.

 

Back to your problem: have the lever of the RF adjusted and all your lenses will focus consistently at all distances. Which is: if a lens back focus at short distance will do the same at longer ones.

This being the case, some shims are required within the two SA

 

Yes thats the case with two of my lenses, back focus at all distances.

 

If a lens is perfect will focus spot on at all distances.

 

I know, my 50 SLX ASPH is spot on at all distances.

 

I hope this will make you pick up the phone and call a trusted shop or the excellent (but not cheap) Leica customer service.

 

My M9 was 7 weeks in Solms, for checking and fix a little loose contact. Costs me 630 EUR. One of the two lenses with the backfocus problem was 5 weeks in solms and still has the issue. I dont think I will give Solms even more money and time to fix the problem.

 

Ciao

Franco

 

Thank you for your explanations!

Edited by rapids41
Link to post
Share on other sites

My rangefinder is already adjustet to my 50 SLX ASPH, which is spot on at all distances now. I think thats the best way because it has the least DOF of all my lenses.

It is not adjusted to one lens - or shouldn't be.It should be adjusted to a fixed standard.

 

 

Are that the two units in this video for which the pipe is needed?

 

 

That sounds interesting. So if I have backfocus at all distances all I have to do is to remove some shims?

No you have to subtract (and/or add or replace) the correct thickness of shims to a tolerance of 0.01 mm on a standarized body.

 

 

Ok ok, I think thats realy a bad idea. You got me. :D

 

 

 

Why? If the lens is ok and I adjust the RF of the camera to that lense, all should be ok!?

 

No. both body and lens must be adjusted to the same standarrd. That is what Leica and good repair shops use reference bodies and lenses for.

 

Ok to adjust the optical SA not, but to add or remove some shims between shouldnt be so difficult.

Indeed not, but putting in the correct thickness and shape of the shim is another story, especially if you have no access to spare parts.

 

 

 

Yes thats the case with two of my lenses, back focus at all distances.

 

 

 

I know, my 50 SLX ASPH is spot on at all distances.

 

 

 

My M9 was 7 weeks in Solms, for checking and fix a little loose contact. Costs me 630 EUR. One of the two lenses with the backfocus problem was 5 weeks in solms and still has the issue. I dont think I will give Solms even more money and time to fix the problem.

 

So send the whole kit to good independent repair shop. You will have to anyway after you have messed things up in DIY.

 

Thank you for your explanations!

Edited by jaapv
  • Like 1
Link to post
Share on other sites

I have sympathy for Rapids41 given his experience with Solms (not universal among Leica users, but reported often enough by forum members), even though I wouldn't touch a complex modern lens with a screwdriver myself. But I do have an older lens that does not focus well on my digital body.

 

No one has yet persuaded me that just fitting a shim is more difficult than adjusting the rangefinder mechanism, especially with a M240 to hand to test it. I am sorry, but being told "just believe" is not helpful in the context of mechanical and optical engineering - we should be more rational than that. I'm open to reason, but not to statements of faith :)

 

As one person has said: you need a set of shims of thickness down to x. Where does one get shims? Buy a load of broken lenses for spares and dismantle them?

 

Edit: a quick google for "optical shims" has partly answered my question, though whether buying one-off new or custom shims is cost effective is another question.

Edited by LocalHero1953
Update
  • Like 1
Link to post
Share on other sites

The simplicity depends on the lens, sure. But don't depend on it. A modern Summilux asph for instance must be adjusted down to a tolerance of 1/1000th of a mm and the Zeiss ZM 28 has individually shimmed elements. Lenses like that are challenging even for an expert.

Age is not always indicative either. A 135 mm Tele-Elmar is a nightmare to do properly.

Edited by jaapv
  • Like 1
Link to post
Share on other sites

No other repair shop will adjust an M9 and lenses here in germany.

The only person I will give a chance is Will Van Manen.

But that will be another 500 EUR.

 

But it will be more expensive if you are unlucky and have to send in a kit that is all over the place.

Not that I find Will very expensive at all, he compares quite favourably to Wetzlar.

Link to post
Share on other sites

I'd start by ensuring the lens mount and camera mount are clean then if you have more than one lens see how the 2m focus is on these and then the infinity focus. The problem you have is it could be camera, lens, or a combination of the both.

 

If you have a friend with a recently adjusted camera, or lens then you can narrow down the problem. There are also lens specialists who will be cheaper than Leica and a better option than having a guess/go.

Link to post
Share on other sites

I had just phoned with Leica.

They promised me it will costs nothing and will only take 2 weeks when I sent all my stuff in again.

I have not much confidence, but we will see in 2 weeks.

Link to post
Share on other sites

My M9 was 7 weeks in Solms, for checking and fix a little loose contact. Costs me 630 EUR. One of the two lenses with the backfocus problem was 5 weeks in solms and still has the issue.

 

...

Link to post
Share on other sites

Just the thought of self adjusting a lens is making me ill.

 

Just like the thought of repairing a car, building a house or sewing a button on a shirt ? :D

 

No, every fix is done right with the correct tools, necessary knowledge, skills and the correct procedures for the job.

 

Sounding from the OPs description none of the above were available at his disposal at the time of need for a fix, so the natural answer of best having the fix done by a qualified service provider surely sounds best fitting.

 

By all means, taking a rasp to a RF coupling flange of a lens sounds a bit drastic at best ;)

 

I am glad, the OP found his way home to Leica. I always found Leica CS fast, courteous and professional.

  • Like 1
Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...