p.1 #1 · Leica M Rangefinder and Lens Calibration Fix
After nearly two years of perfect calibration, my M10-R recently went slightly out of adjustment. Since I frequently change lenses and have taken this camera to national parks by car and to other countries by plane, it’s inevitable that the alignment drifts a bit over time.
However, it was a quick fix for me. All you need is a 2mm hex key (I have this one) to rotate the "cam". This is commonly known as horizontal rangefinder calibration. My camera was back-focusing, so I had to rotate the cam clockwise just a bit.
For precise adjustment, I use a telephoto lens that I know is perfectly calibrated with the rangefinder. In my case, that’s the Leica 90mm f/2 AA. This lens is accurately adjusted from MFD to infinity, so I typically calibrate the rangefinder at around 2m using an indoor target. The lens has a short focus throw, requiring only a slight rotation to achieve focus, which allows for very accurate adjustments. I recommend using a telephoto lens with a short focus throw for this calibration, though a 50mm f/1.4 lens would work well too.
p.1 #4 · Leica M Rangefinder and Lens Calibration Fix
Timely post! I did this just yesterday... I kept missing focus on my son by enough-to-be-noticeable but chalked it up to me not being perfect with my focus and my kiddo being in a state of perpetual motion. I finally did some precision testing, and it turns out my calibration was off!
I called DAG, and he was so kind to walk me through a good methodology to test/confirm a calibration issue: 1. fixing the position of the camera, 2. placing a yard-stick (or tape measurer) at a 45 degree angle to the camera, 3. taking test shots (focus on a number and see if that one is in focus on the shot/EVF) to confirm it's a rangefinder calibration issue and not a me issue...
Anyhow, I was able to confirm it and fix it using a similar method Fred described. It's easy enough to do and even just those few inches made a world of difference... the down side is I've eliminated a useful excuse...
p.1 #5 · Leica M Rangefinder and Lens Calibration Fix
Just to clarify, these instructions are for adjusting the camera’s rangefinder. When a lens is perfectly aligned with the Leica rangefinder tolerance, it should provide 100% accuracy in focusing.
However, as many of you know, not all lenses are perfectly adjusted, even Leica lenses. Testing this when buying a new or used lens can be stressful, especially when you’re unsure of the lens’s calibration.
If you’re confident that your camera’s RF is accurate but the lens isn’t focusing properly, particularly wide open, the issue likely lies with the lens. Usually, the lens needs to be adjusted, either by modifying the helicoid or adjusting internal shims.
Here’s a summary I wrote for myself, which could be helpful for anyone facing this issue:
Lens Calibration Issues:
Quick Guide: Fixing Front-Focus or Back-Focus on Rangefinder Lenses
1. Focus using Live View (LV) for accurate focus.
2. Check the Rangefinder Patch – If it does not align, note the direction you must turn the focus ring to align it. (Ensure you are behind the camera in the normal shooting position).
Quick Rule of Thumb:
• If you turn the focus ring clockwise (toward infinity) to align the patch, the lens is front-focusing – Remove shims or shave mount.
• If you turn the focus ring counter-clockwise (toward MFD) to align the patch, the lens is back-focusing – Add shims
p.1 #6 · Leica M Rangefinder and Lens Calibration Fix
Fred, could you clarify whose perspective you mean by CCW and CW? From "Photographer's perspective", moving the focus ring CCW (AKA towards infinity) is the equivalent of turning it CW from "Subject's perspective". A small thing, but it bears mentioning.
p.1 #7 · Leica M Rangefinder and Lens Calibration Fix
Pindy wrote:
Fred, could you clarify whose perspective you mean by CCW and CW? From "Photographer's perspective", moving the focus ring CCW (AKA towards infinity) is the equivalent of turning it CW from "Subject's perspective". A small thing, but it bears mentioning.
It refers to rotating either counterclockwise or clockwise, similar to the motion of a clock. I understand this is crucial, as the correct adjustment depends on getting this right.
Jan 28, 2025 at 09:53 AM
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p.1 #8 · Leica M Rangefinder and Lens Calibration Fix
Pindy wrote:
Fred, could you clarify whose perspective you mean by CCW and CW? From "Photographer's perspective", moving the focus ring CCW (AKA towards infinity) is the equivalent of turning it CW from "Subject's perspective". A small thing, but it bears mentioning.
If you imagine a clock on the front of the camera, with the 12 on top, a 3 to the right as you look at it, a six on the bottom and a 9 on the left, then perspective won't matter. I get what you are saying, but if you think about it this way you will be fine.
p.1 #9 · Leica M Rangefinder and Lens Calibration Fix
Fred Miranda wrote:
It refers to rotating either counterclockwise or clockwise, similar to the motion of a clock. I understand this is crucial, as the correct adjustment depends on getting this right.
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Steve Spencer wrote:
If you imagine a clock on the front of the camera, with the 12 on top, a 3 to the right as you look at it, a six on the bottom and a 9 on the left, then perspective won't matter. I get what you are saying, but if you think about it this way you will be fine.
“In front of the camera…as you look at it”, is “subject’s perspective”. Mystery solved.
I had to ask because when I have a camera to my face, and I’m “looking through it”, my clockwise is another man’s counter clockwise.
Nevertheless, this fix worked for me, so thank you for the info.
p.1 #10 · Leica M Rangefinder and Lens Calibration Fix
Adjusting with the hex can solve calibration issues, but I have found the the process of adjusting with the hex for infinity, then adjusting the travel of the cam corrects for close up— it’s a process of adjusting one, then the other, then touching up the adjustments until you are good from minimum to infinity.
This tutorial uis VERY good- once you do it a couple times, it becomes second nature: https://www.l-camera-forum.com/topic/118043-m9-coincidence-at-infinity/
p.1 #11 · Leica M Rangefinder and Lens Calibration Fix
mdg137 wrote:
Adjusting with the hex can solve calibration issues, but I have found the the process of adjusting with the hex for infinity, then adjusting the travel of the cam corrects for close up— it’s a process of adjusting one, then the other, then touching up the adjustments until you are good from minimum to infinity.
This tutorial uis VERY good- once you do it a couple times, it becomes second nature: https://www.l-camera-forum.com/topic/118043-m9-coincidence-at-infinity/
I’ve nearly made it through that thread and it is so old that many of the helpful images are broken links. Plus you have to wade through a few pages of fighting with Jaap (take a number!). I would love it if the details, which are a little hard to follow without visuals, could be condensed into a succinct set of instructions, apart from the back and forth forum chatter.
p.1 #12 · Leica M Rangefinder and Lens Calibration Fix
Pindy wrote:
I’ve nearly made it through that thread and it is so old that many of the helpful images are broken links. Plus you have to wade through a few pages of fighting with Jaap (take a number!). I would love it if the details, which are a little hard to follow without visuals, could be condensed into a succinct set of instructions, apart from the back and forth forum chatter.
Everything you need in that thread is contained in posts # 8, 9, 10, 15.
I saved a screenshot of 15, and was off to the races.
It really is not difficult if you remember to maintain a light touch.
p.1 #13 · Leica M Rangefinder and Lens Calibration Fix
mdg137 wrote:
Everything you need in that thread is contained in posts # 8, 9, 10, 15.
I saved a screenshot of 15, and was off to the races.
It really is not difficult if you remember to maintain a light touch.
Most rangefinder misalignments are easy to fix by adjusting the roller. However, as you pointed out, the arm mechanism length can also be adjusted. I’ve never needed to adjust the arm mechanism, though, and have found that a simple and quick adjustment to the roller distance resolves most RF issues.
p.1 #14 · Leica M Rangefinder and Lens Calibration Fix
I recently purchased a used M10 and the Ultron 28/2 (version 2). I have this problem where it feels like no matter how much im rotating the horizontal rangefinder alignment counterclockwise, I still need to push the focus out to get it accurate. Any ideas? I have spent hours trying to make adjustments. I can make it worse but never seem to be able to improve past a certain point. Might be a problem with the lens too, but I dont know how to figure it out.
p.1 #15 · Leica M Rangefinder and Lens Calibration Fix
Your issues are that 1. You have one lens and you don’t know if it’s good and 2. The 28 is too wide to make this an easy process. It could also be that the cam arm length is set wrong (there’s actually three calibration points for a rangefinder. The roller just sets the infinity point). This is not something you can do yourself. It requires specialist equipment. But a few ideas.
Try calibrating a a mid distance and infinity (say a km or so). Calibrating at close is more difficult. Mid will at least make the lens usable.
In your case either find someone who shoots M and buy them a beer while you calibrate using a longer lens that’s known to be good or take the camera to Leica and have it done properly and then you’ll know if the lens is out and deal with that.
I’ve self calibrated for years but even I send cameras and lenses in for a couple of reasons. 1 is problem calibrations and 2 is if I’m selling cameras. I have 3 M’s in with Leica currently because although I know I can do it and have done for a decade or more, I also know I can’t match their optical bench.
p.1 #16 · Leica M Rangefinder and Lens Calibration Fix
Gordon, thank you for the insight and tips, much appreciated. The focus image moves past the focusing patch at infinity; I am able to adjust it closer to the focusing patch, but eventually it will start again further away. I tried calibrating both at infinity and 1 meter. In any case, I also noticed that the sensor on this camera was exceptionally dirty (visible smudges at f2 and at f22… oh boy) so I am leaning towards returning it. I got it an attractive price but to me it seems it is in need of proper maintenance that will cancel out my savings.
p.1 #17 · Leica M Rangefinder and Lens Calibration Fix
flash wrote:
Your issues are that 1. You have one lens and you don’t know if it’s good and 2. The 28 is too wide to make this an easy process. It could also be that the cam arm length is set wrong (there’s actually three calibration points for a rangefinder. The roller just sets the infinity point). This is not something you can do yourself. It requires specialist equipment. But a few ideas.
Try calibrating a a mid distance and infinity (say a km or so). Calibrating at close is more difficult. Mid will at least make the lens usable.
In your case either find someone who shoots M and buy them a beer while you calibrate using a longer lens that’s known to be good or take the camera to Leica and have it done properly and then you’ll know if the lens is out and deal with that.
I’ve self calibrated for years but even I send cameras and lenses in for a couple of reasons. 1 is problem calibrations and 2 is if I’m selling cameras. I have 3 M’s in with Leica currently because although I know I can do it and have done for a decade or more, I also know I can’t match their optical bench. Gordon...Show more →
That makes sense. It is harder to calibrate the rangefinder yourself if you are not sure whether your lens is fully adjusted. As Gordon mentioned, using a longer and faster lens gives you more confidence in the adjustment. I usually prefer a 50mm f/1.4 or a 90mm f/2 for this.
I typically make the adjustment at a distance of 2m but test at other distances as well. Sometimes, the lens coupling is not manufactured accurately across the full focus range, or the rangefinder arm might need additional fine-tuning.
p.1 #19 · Leica M Rangefinder and Lens Calibration Fix
maxonenn wrote:
Gordon, thank you for the insight and tips, much appreciated. The focus image moves past the focusing patch at infinity; I am able to adjust it closer to the focusing patch, but eventually it will start again further away. I tried calibrating both at infinity and 1 meter. In any case, I also noticed that the sensor on this camera was exceptionally dirty (visible smudges at f2 and at f22… oh boy) so I am leaning towards returning it. I got it an attractive price but to me it seems it is in need of proper maintenance that will cancel out my savings....Show more →
In my experience, the adjustment that Fred describes might be the most common way for a RF to drift. My hunch. I’ve carried a 2mm in my spare battery case for years often having to make the adjustment after the camera has been on an airplane. I am a retired airline pilot and my camera saw a lot of travel with me and I would always check focus with my 50 summilux arriving at destination and often have to make an adjustment. Point it out the hotel window at a very distant object and observe the rf alignment at infinity… Too often it was out and could be brought back to spec with a couple iterative adjustments and then confirmed by a mid distance “test”. If I had sent my camera to Leica for an adjustment like this every time it drifted i wouldn’t own the camera, I would’ve sold them (M11and M11M) years ago. It is frustrating that they should drift like this, but they do.
p.1 #20 · Leica M Rangefinder and Lens Calibration Fix
Fred Miranda wrote:
That makes sense. It is harder to calibrate the rangefinder yourself if you are not sure whether your lens is fully adjusted. As Gordon mentioned, using a longer and faster lens gives you more confidence in the adjustment. I usually prefer a 50mm f/1.4 or a 90mm f/2 for this.
If you have several lenses, it may not be possible to calibrate your camera for all of them.
A while ago, you could send all your gear to Leica and they would calibrate all the lenses to a standard and then the camera.
A Leica repair shop checked my M11 so I'm sure it is perfectly calibrated, I've also compared it with other cameras but I often need to adjust my Voigt lenses themselves.
Fred Miranda wrote:
I typically make the adjustment at a distance of 2m but test at other distances as well. Sometimes, the lens coupling is not manufactured accurately across the full focus range, or the rangefinder arm might need additional fine-tuning.
I make the adjustment at a longer distance using a dedicated 3D focus chart, around 5m, then check the infinity focus and around 1m.
