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Minor front focus - level of acceptability?


placeisthespace

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Hi everyone,

 

I am the owner of a new Leica MP and along with a new 24mm Elmar. When I took it out today for some photos, I noticed that when focusing on objects far away (1-2km) at infinity, the focus tab stops just before the patches are fully aligned (~1mm more to go), which I gather is a front focus misalignment. I also have a 35mm Summilux FLE and 35mm Summicron, and while they align much better (maybe ~0.5mm to go), the Elmar is slightly worse.

 

The question I have is how likely will this amount of front focusing be apparent in normal sized prints, especially if my photos tend to be more concentrated on landscape shots. Also, I tend to shoot with F4 and up. I searched, and while there are plenty of topics on focus issues, I couldn't find one similar to my issue.

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Chances are the issue is just with the rangefinder and not the actual lens optics and the images may be fine. Even if the lens is truly off, a 24mm lens with an f3.8 maximum aperture will have a lot of 'fudge" room on the depth of field side.

 

On the other hand, I just sent my 75mm f2 APO off to DAG. The rangefinder on my M262 was calibrated just a few months ago by Leica and works perfectly with all my other lenses but the 75mm is focusing behind the subject showing as "in focus" using the rangefinder. Frustrating as heck.

 

If you have other lenses where the rangefinder is off, and it sounds like you do, that sounds like your camera needs an adjustment. The longer/faster the lens, the more of a problem you will have. If it was my camera, I'd send it in.

Edited by Gregm61
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2 out of 4 of my most recent M lens new purchases, had to go straight back to the factory to be re-calibrated. I really cannot understand why, at the price they are (one of the lenses was a Noctilux), they cannot put each lens on a perfectly calibrated camera from the M240 family. This tests for optical against RF calibration in seconds. It is what I do with every lens acquisition. Strangely my two most recent purchases, both used LTM lenses, a 35/2.8 Summaron and an 85/1.5 Summarex, even though 57 and 64 years old respectively, albeit in very nice condition, were both perfectly calibrated.

 

Wilson

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Hi everyone,

 

I am the owner of a new Leica MP and along with a new 24mm Elmar. When I took it out today for some photos, I noticed that when focusing on objects far away (1-2km) at infinity, the focus tab stops just before the patches are fully aligned (~1mm more to go), which I gather is a front focus misalignment. I also have a 35mm Summilux FLE and 35mm Summicron, and while they align much better (maybe ~0.5mm to go), the Elmar is slightly worse.

 

The question I have is how likely will this amount of front focusing be apparent in normal sized prints, especially if my photos tend to be more concentrated on landscape shots. Also, I tend to shoot with F4 and up. I searched, and while there are plenty of topics on focus issues, I couldn't find one similar to my issue.

 

 

if the lens stops short of infinity the most usual cause is the roller wheel being off. Fortunantely thi is an owner-adjustment. Use a hex key 2 mm to give a minimal adjustment to the rangefinder roller that you can see in the camera mouth.

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Jaap,

 

The problem with just one lens and one camera, without live view, is that you can end chasing your own tail. With the RF, it could be the infinity roller, rate elbow or even a prism problem. With the lens, it could be the shim adjustment on the mount, the optical cell in the body, the RF slope or the helicoid. I have had pretty much all of these problems over the years on Leica or Leica fit lenses and bodies. I have just returned a Leotax LTM clone to the service people, as its infinity was off (checked with three lenses) and was not correcting with the infinity screw behind the corner of the VF window. Something has come adrift or not been reconnected after the CLA.

 

So if you just correct the infinity roller, I feel it is essential to make focus checks with an angled focus diagram, at various distances afterwards. Say 1m, 2.5m, 6m and 20m, the later for longer lenses only.

 

Wilson

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  • 2 weeks later...

Just a small update --

 

In the meantime, I received a new M10. When I attached the lenses from earlier, the slight misalignment on the rangefinder is gone. So my hunch is that it's the MP that is out of focus and needs to be adjusted. Fortunately, I'll be visiting New Jersey next week, and they said I can bring it in person. I could adjust it myself, but I'll have a heart attack if I screw anything up.

 

Is it normal for new cameras (in this case a brand new Leica MP film) to have their rangefinders misaligned? i never dropped it and I handled it pretty delicately. Wouldn't this be something they test after assembly? Is this misalignment something that will likely come back in the future?

 

Albert

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I had this issue and sent my camera and lens in. Leica made it worse. I used the thread on this forum to provide courage to tweak the screw with a 2mm hex wrench. It fixed everything. You don't need to move the screw much. Just tap the wrench a bit with a finger then check focus. If you overdo it tap the wrench a bit the other way. It actually seems scary but is very minor.

 

 

Sent from my iPad using Tapatalk

Edited by FeralCoton
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