DIY Leica M rangefinder adjustment

[Huss]

My M7's rf drifted, again, after about 20 rolls. Again it wouldn't focus to infinity. With all the (numerous) Leica and other glass that I tried. Before I would grit my teeth, pack it up, pay the $50 for insured to actual value and send it to one of the experts.
Today I cried out "ENOUGH!". And went to google.

Holey moley is it easy to adjust this yourself! I just followed this video and used a 2mm hex wrench. Took about 5 minutes in total, making gradual adjustments, using the moon as my infinity target.



It's weird, it's made me appreciate Leica M cameras much more now, because there no longer is that nagging feeling of having to deal with focus issues. Being able to sort it out yourself is very rewarding and makes the camera become more a tool than an object to be pampered..

p.s. if your M does not reach infinity, you need to turn the wrench anti-clockwise.

 

[Huss]

Developed my test roll. This method works perfectly. Everything from 1.2 @ min distance to shooting at infinity is sharp.

 

[Horatio]

Thanks for the tip.

 

[DonW]

Thanks! Saved the utube to my bookmarks.

 

[BSP]

This make wonder what the other, more hidden, adjustment device does. The one behind the top plate.

 

[bdial]

This make wonder what the other, more hidden, adjustment device does. The one behind the top plate.

I believe the other adjustment is for vertical alignment.

 

[Steve@f8]

I was under the illusion that there were two adjustments for RF focus adjustment: minimum focus and infinity. Not so, it appears. Correcting infinity corrects minimum focus too?

Take Leica as an example, they set the RF to a standard that does not involve mounting a camera lens. The DIY method assumes the lens is within tolerance.

 

[Huss]

I was under the illusion that there were two adjustments for RF focus adjustment: minimum focus and infinity. Not so, it appears. Correcting infinity corrects minimum focus too?

Take Leica as an example, they set the RF to a standard that does not involve mounting a camera lens. The DIY method assumes the lens is within tolerance.

I cannot see how there can be multiple adjustments settings for different distances as there is only one physical adjustment that you can make. i.e there is only one dial to turn for horizontal adjustment. Adjusting my camera for infinity provided for correct focus at all distances.

The vertical adjustment in my camera was fine. If it is like my Xpan, the vertical adjustment (if off) needs to be adjusted first before the horizontal adjustment.

Leica setting the RF to a standard that does not involve mounting a lens relies on an acceptable range of tolerances. It would explain why my brand new M-E's RF was slightly off. The standard adjustment was incorrect due to mfg tolerances, or intolerances as in my case.

A heads up. This setting of the RF that I used DOES NOT WORK with 7Artisans lenses. Every 7A lens I own (28 1.4, 35 f2, 50 1.1 x2) focuses PAST infinity at the hard stop. But it focuses correctly via the RF, you just cannot use the hard infinity stop as infinity. This is because 7A lenses essentially leave the final amount of lens focus fine tuning to the customer, for better or for worse. You can move the rf connecting ramp on the lens mount by loosening a screw. What you are meant to do after confirming that the focus is correct via the camera's RF, is then focus on something at infinity using the RF. Then you loosen a few screws holding the focus ring, and while making sure to not change the position of focus, rotate the ring so that the infinity hard stop is at that point. Then re-tighten the screws.
I haven't bothered to do this with any of my 7A lenses, as I just use the RF. But this is all a slight digression...

 

[Steve@f8]

Thanks Huss,
I’ve been thinking about it since my post above. What you’ve mentioned makes absolute sense to me now, for If Leica had designed the RF to have two horizontal adjustments - near and far - it would be an incredibly complex iterative set up and as a design concept a non starter back in the 50’s when it was introduced into the M.
I have two Ms, an M6 and an M240, four lenses: 7A 28/1.4, Summicron 35/f2, Summilux 50/1.4 and a Summicron 90/f2, and on the M240 I’m aware minimum focus is not correct with any of the lenses when used wide aperture. With the M6 I don’t bother to look so close at the negatives and in any case I tend to use the camera for a different style of photography, eg street reportage. I’ve been quite nervous about touching the M240, and heard (again a bit of hearsay) that Leica set the adjustment Allen screws with Loctite and heat or brute force is required to make any adjustment possible. In an ideal world I’d have a beater M to play with, or a camera belonging to someone else () so I could practise before touching my digital M.

 

[Вormental_old]

Having to adjust every 20 rolls doesn't sound right.

 

[Huss]

... I’ve been quite nervous about touching the M240, and heard (again a bit of hearsay) that Leica set the adjustment Allen screws with Loctite and heat or brute force is required to make any adjustment possible. In an ideal world I’d have a beater M to play with, or a camera belonging to someone else () so I could practise before touching my digital M.

I just checked my M240. It's just like my M7 - no loctite etc. Just need a 2mm allen key.

 

[Steve@f8]

I just checked my M240. It's just like my M7 - no loctite etc. Just need a 2mm allen key.

Excellent, thank you Huss you’re a star!

(BTW, I can tell you that you’re missed on the ‘other place’.)

 

[E. von Hoegh]

Having to adjust every 20 rolls doesn't sound right.

It isn't right.
Of my 9 current rfs, including two Kievs, a pair of Canon IIbs, Contax II, Zorki - S, Canonet 19, Kodak 35rf and a Linhof, none have drifted at all, and I've had them at least 5 years; 33 yrs. for the Linhof. I have reason to believe that the Kievs, the Contax, the Linhof, and the possibly Canonet are still on the original factory adjustment.
Nor did my two M3s, IIIg, Canonet 17 g3, or previous Kodak 35rf.

 

[Huss]

All my Ms have drifted in use. And I have a lot.
Actually I take that back. My MdA has not...

There's a reason Leica (and others) provide a way to bring it easily back to spec.
Even my little Agfa Optima 1535 has a little portal that you uncover to tune the RF.
Perhaps I am more obsessive than others with focus accuracy.

 

[Huss]

Excellent, thank you Huss you’re a star!

(BTW, I can tell you that you’re missed on the ‘other place’.)

A pleasure Steve, glad it helped.

 

[Steve@f8]

A pleasure Steve, glad it helped.

Just occurred to me... on the first postulate... there’s only one horizontal adjustment. Let’s say near focus is out, but infinity appears to be ok with the superimposed images aligning. Does it suggest the lens is at fault, or would it be appropriate to adjust the camera? I’m convinced there’s only one adjustment, I just can’t get my head around the possibility of near focus being out of cal but infinity being correct. Any thoughts, Huss or anyone else?

I would just add that infinity is really unimportant to me, and on the rare occasion I make a photo at a large distance the aperture is closed appropriately. I’m more of a mid to near distance person.

 

[E. von Hoegh]

I was under the illusion that there were two adjustments for RF focus adjustment: minimum focus and infinity. Not so, it appears. Correcting infinity corrects minimum focus too?

Take Leica as an example, they set the RF to a standard that does not involve mounting a camera lens. The DIY method assumes the lens is within tolerance.

Correct. (DIY can mean "destroy it yourself" which, I guess, is better than paying to have it done).
Back in the screwmount days, Leitz used gauges which mounted in place of the lens. There were several, calibrating the rf at points (say, minimum, 2m, 5m, 10m, "infinity"). The lenses were calibrated separately, first by holding the tolerance of actual focal length as close as possible, second by tweeking the face cam in the lens mount. The mechanism of the rf is very simple, if kept clean and treated with the respect due a precision device there is no reason for it to misbehave.
Handling the camera roughly, careless interchange of lenses, debris in the mechanism, and poor lubrication are the likeliest causes of erratic behaviour.

 

[E. von Hoegh]

Just occurred to me... on the first postulate... there’s only one horizontal adjustment. Let’s say near focus is out, but infinity appears to be ok with the superimposed images aligning. Does it suggest the lens is at fault, or would it be appropriate to adjust the camera? I’m convinced there’s only one adjustment, I just can’t get my head around the possibility of near focus being out of cal but infinity being correct. Any thoughts, Huss or anyone else?

I would just add that infinity is really unimportant to me, and on the rare occasion I make a photo at a large distance the aperture is closed appropriately. I’m more of a mid to near distance person.

There is an adjustment ( sometimes several)for slope on all precision rangefinders, usually it's the roller on the arm (just inside the top of the lens mount) which follows the lens cam; this is mounted on an adjustable eccentric, adjusting which changes the effective length of the arm & thus the slope, presuming the lens is within tolerance.

 

[Mihai And]

Just occurred to me... on the first postulate... there’s only one horizontal adjustment. Let’s say near focus is out, but infinity appears to be ok with the superimposed images aligning. Does it suggest the lens is at fault, or would it be appropriate to adjust the camera? I’m convinced there’s only one adjustment, I just can’t get my head around the possibility of near focus being out of cal but infinity being correct. Any thoughts, Huss or anyone else?

I would just add that infinity is really unimportant to me, and on the rare occasion I make a photo at a large distance the aperture is closed appropriately. I’m more of a mid to near distance person.

For the Leica M there are 2 horizontal adjustments. The first sets the focus at infinity (2mm screw inside the roller on the focusing arm). The second shortens and lengthens the arm for adjusting focus throw (calibration at short distance focus while infinity is already calibrated). See this video for the horizontal adjustment:
As I understand there is a third adjustment for the vertical alignment that can be done by using a special tool and is accessed by removing the Leica logo in front of the camera. Se this video:
This is what I found when researching how to adjust my camera and I am not an expert on the subject. Of course everyone does it on his own risk.

 

[guangong]

Thanks. Nice to know although my Ms, through M3 to M5 have never suffered any focusing issues in over 50 yrs, that is no guarantee against future.