Lost Coupling: M9 + 35 Lux

[efftee]

Advertisement (gone after registration)

Several times this evening, I lost the ability to focus my M9 with a 35 Lux, ie there was nothing to align through the viewfinder -- turning the focusing ring had no effect through the viewfinder. I can only assume that it lost RF coupling. Turning the camera off and on again solved the problem for a while, until it happened again, that is. The battery was at 75%; I cannot imagine what could've caused it. I've never experienced this problem with this 35 Lux or any other lenses with my M8 before, and it didn't occur while I was playing around with the M9 over the weekend (I just got it on Fri) with my 50 Lux.

 

Anyone else had this problem before? What should I do?

[Advertisement]

The Leica Q3 is available for pre-order at B&H Photo Video and Adorama

[cocker]

Finger on the rangefinder window? RF coupling is nothing to do with the electronics of the camera. Its mechanical

[ashwinrao1]

Leica is readying you for the purchase of a new 35 'lux asph...

[01af]

What should I do?

Watch your fingers.

[efftee]

Finger on the rangefinder window? RF coupling is nothing to do with the electronics of the camera. Its mechanical

 

When the RF window is blocked, the small focusing square should disappear but it didn't. Partially perhaps? But I've never encountered this problem before so why only now; my finger didn't grow any longer. I'll monitor it for a while longer and see if it happens again. Thanks.

[dpattinson]

I guess if the armature that holds the wheel in the focusing mechanism is a little sticky, you could experience intermittent loss of focusing ability. It might just be that the 35 couples in some way that the arm is left in its 'sticky' position, but the 50 never does.

[adan]

Advertisement (gone after registration)

Forget turning the camera on and off or the battery, or anything else electrical. Whatever this is, it is purely mechanical/physical - there is no part of the lens/rangefinder/viewfinder linkage that can be turned on or off. (However, if Toyota made rangefinders... )

 

I wouldn't expect it to be any part of the lens/RF linkage if it comes and goes. Those are pretty hard-wired links of helicals, cams, and levers. If something came loose, it would stay loose, and not be intermittent. The exception would be if something opaque came loose internally and covered the light path from the RF window - but as with a finger, that would presumably block out the window outline, not just the image within.

 

IF...you had the camera set to one focus extreme or another, and were viewing a subject at the other extreme, it can sometimes happen that the images are so far misaligned (correctly, showing extreme mis-focus) that no part of the subject is visible in both of the two RF images - the RF window may be looking at blank wall while the main viewfinder is aimed at someone's face. Unless you turn the lens far enough in the appropriate direction to get close to correct focus, you'll not see anything recognizable to align between the two images.

 

IF...you have a fingerprint on the small RF window, it can reduce the contrast of the RF image so much that the second moving image from that window is hard to see. Depends on lighting - low light ("this evening") can make it worse. But if you change to a more contrasty subject, or brighter light (closer to a lamp) the extra brilliance will burn through the fingerprint.

 

Rarely, the RF link will run out of travel at the minimum focus end before the lens does. It may stop precisely at .7 meters while the lens goes a little beyond (closer than) the .7 meter mark. I had a camera and 50mm lens combo that did this. I also had a 35 'lux pre-ASPH where the M9's RF cam hit the rear element of the lens and stopped moving for the last mm or so of the lens travel (the lens would focus a tad closer than 1 meter, but the RF image quit moving exactly at 1 meter).

 

But in those cases there should still be a double image visible - it just won't move.

[250swb]

If its none of the things Andy has mentioned are the 35mm/135mm framelines still visible when the problem occurs? I just wonder if you have turned the lens over centre when mounting it, easily possible if you keep your finger on the lens release button. Let the lens click into place if this seems like the cause.

 

Steve

[jaapv]

Totally covering the RF window with the finger does cause the RF patch to disappear, but only partially covering it or holding the finger or camera strap in front of it at a distance that allows light to fall on the window will certainly produce the effect the OP describes.

[Fotofanatiker]

Funny - I had exactly the same issue yesterday with my M9 / SX24 combo when shooting during day light for the first time... I thought it might have something to do with the light but in the end I decided that it's simply a lack of experience, got my camera early this week and I'm still learning...

[efftee]

I guess if the armature that holds the wheel in the focusing mechanism is a little sticky, you could experience intermittent loss of focusing ability. It might just be that the 35 couples in some way that the arm is left in its 'sticky' position, but the 50 never does.

 

Um, David, I'm afraid that's quite Greek to me...

[efftee]

Forget turning the camera on and off or the battery, or anything else electrical. Whatever this is, it is purely mechanical/physical - there is no part of the lens/rangefinder/viewfinder linkage that can be turned on or off. (However, if Toyota made rangefinders... )

 

I wouldn't expect it to be any part of the lens/RF linkage if it comes and goes. Those are pretty hard-wired links of helicals, cams, and levers. If something came loose, it would stay loose, and not be intermittent. The exception would be if something opaque came loose internally and covered the light path from the RF window - but as with a finger, that would presumably block out the window outline, not just the image within.

 

IF...you had the camera set to one focus extreme or another, and were viewing a subject at the other extreme, it can sometimes happen that the images are so far misaligned (correctly, showing extreme mis-focus) that no part of the subject is visible in both of the two RF images - the RF window may be looking at blank wall while the main viewfinder is aimed at someone's face. Unless you turn the lens far enough in the appropriate direction to get close to correct focus, you'll not see anything recognizable to align between the two images.

 

IF...you have a fingerprint on the small RF window, it can reduce the contrast of the RF image so much that the second moving image from that window is hard to see. Depends on lighting - low light ("this evening") can make it worse. But if you change to a more contrasty subject, or brighter light (closer to a lamp) the extra brilliance will burn through the fingerprint.

 

Rarely, the RF link will run out of travel at the minimum focus end before the lens does. It may stop precisely at .7 meters while the lens goes a little beyond (closer than) the .7 meter mark. I had a camera and 50mm lens combo that did this. I also had a 35 'lux pre-ASPH where the M9's RF cam hit the rear element of the lens and stopped moving for the last mm or so of the lens travel (the lens would focus a tad closer than 1 meter, but the RF image quit moving exactly at 1 meter).

 

But in those cases there should still be a double image visible - it just won't move.

 

Andy, first off, thanks for the 360 on the matter. Thing is, (1) though it's not electrical, the problem did go away when I turned the camera off and back on. That could have been due to any partial blockage being resolved with the physical act of turning it off and on again.

 

(2) It was evening but I was indoor and the place was well lit. I clearly remember the RF square being present as everything within that area was always in focus regardless of the focusing back and forth.

 

(3) I do wipe/clean the windows often, as I recognize fingerprints do get on them and make everything look hazy.

 

(4) I really doubt it's my finger (I tried positioning my finger to partially block the RF window and it was way uncomfortable for me to have been doing it) or the strap (I couldn't even re-enact a situation when the strap could fall in front of the window, let alone have it happen several times repeatedly).

 

I couldn't fathom what it could be but I will look out for it.

[efftee]

If its none of the things Andy has mentioned are the 35mm/135mm framelines still visible when the problem occurs? I just wonder if you have turned the lens over centre when mounting it, easily possible if you keep your finger on the lens release button. Let the lens click into place if this seems like the cause.

 

Steve

 

Hi Steve, not really sure what you mean about the mounting. The framelines and RF patch at the center were all present.

[efftee]

Totally covering the RF window with the finger does cause the RF patch to disappear, but only partially covering it or holding the finger or camera strap in front of it at a distance that allows light to fall on the window will certainly produce the effect the OP describes.

 

Hi Jaap, I tried to re-enact the finger to partially block the window, it's quite a stretch for me and truly uncomfortable -- it's quite impossible for me to operate the camera at that position. Plus this hadn't happen in the past with my M8, so I really don't think it's my finger.

[efftee]

Funny - I had exactly the same issue yesterday with my M9 / SX24 combo when shooting during day light for the first time... I thought it might have something to do with the light but in the end I decided that it's simply a lack of experience, got my camera early this week and I'm still learning...

 

Hey there, do share if experience it again. It's probably some silly thing.

[jaapv]

Hi Jaap, I tried to re-enact the finger to partially block the window, it's quite a stretch for me and truly uncomfortable -- it's quite impossible for me to operate the camera at that position. Plus this hadn't happen in the past with my M8, so I really don't think it's my finger.

I find it quite easy t o do, but if not,then it must have been the carrying strap - it cannot have been anything silly like a prism working loose, because it would happen with all lenses.

[dpattinson]

Um, David, I'm afraid that's quite Greek to me...

 

Ah, if you take the lens off and look inside the camera - then you will see a small articulated arm supporting a metal roller at the top of the lens mount opening. That roller is pushed back when the lens focus is changed and is what couples the lens to the rangefinder.

 

I was suggesting that if that articulated arm was 'sticky' at some position, then you might get temporary disengagement from the rangefinder.

 

Do you know if this was happening at very close distances? As mentioned above, some lenses do rotate beyond the rangefinder coupling and you see the RF patch not move in that range (usually the absolute minimum range of the lens).

[efftee]

I find it quite easy t o do, but if not,then it must have been the carrying strap - it cannot have been anything silly like a prism working loose, because it would happen with all lenses.

 

Your hands must be considerably larger than mine. I just tried again; very difficult. And the strap, still couldn't make it happen.

 

I didn't take many shots with the 50 Lux over the weekend, maybe 30 shots. Then around 100+ shots with the 35 Lux last night. For all you know, it could happen with the 50 Lux too given time. But fwiw, I couldn't make it happen again today.

[Advertisement]

Hallo,

Look here: Leica M

[efftee]

Ah, if you take the lens off and look inside the camera - then you will see a small articulated arm supporting a metal roller at the top of the lens mount opening. That roller is pushed back when the lens focus is changed and is what couples the lens to the rangefinder.

 

I was suggesting that if that articulated arm was 'sticky' at some position, then you might get temporary disengagement from the rangefinder.

 

Yeah, I see it, pushed it even. Don't seem sticky at all.

 

Do you know if this was happening at very close distances? As mentioned above, some lenses do rotate beyond the rangefinder coupling and you see the RF patch not move in that range (usually the absolute minimum range of the lens).

 

I was rotating it clockwise and anticlockwise from beginning to end and back again. Nada. I'm just going to keep at it and see if it happens again.

 

Thanks.

[ho_co]

I think Mark Norton reported that in a few cases the tracking roller can slip off the rangefinder cam.

 

Problem with that explanation is that it's repeatable, and certainly doesn't clear itself when you take the camera away from your face.