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Nikon Lenses on M240


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So guys, you have me a bit confused.

I am aware how the mechanical rangefinder of the Leica M works up to the M9 generation of cameras and have worked with them.

 

Does the M10 generation of digital M cameras introduce a sensor to the mechanical rangefinder mechanism to sense motion of the focus ring and if this is the method, where does this sensor sit (illustrations / drawings)?

Is it a sophisticated sensor (potentiometer, linked to software, "knowing" about focal length, … ) or just a dumb sensor, sensing motion of the RF arm?

In Live View mode the camera detects the contrast between edges and when at it's maximum that is when that part of the image is in focus, the image on the LCD or in the EVF shows a thin red line around the relevant object as confirmation. You can also focus visually with Live View without the focus peeking if you prefer. Ideally to use the feature accurately you either need a tripod with just the LCD as it is difficult to hold and fine focus at arms length, or with the EVF you can use the camera hand held as usual. There is no mechanical or electronic connection between the lens and body needed to achieve this, which is why almost any non-Leica 35mm SLR lens can be used on an M240 body with an appropriate adapter. It should be noted that to fine focus you open the aperture up to maximum, if you want to zone focus you can have it stopped down to whatever, say f/8, and the focus peeking with indicator will show all the areas that are in focus, but not necessarily critically in focus as per normal zone focusing with an M lens.

 

Steve

Edited by 250swb
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In Live View mode the camera detects the contrast between edges and when at it's maximum that is when that part of the image is in focus, the image on the LCD or in the EVF shows a thin red line around the relevant object as confirmation. You can also focus visually with Live View without the focus peeking if you prefer. Ideally to use the feature accurately you either need a tripod with just the LCD as it is difficult to hold and fine focus at arms length, or with the EVF you can use the camera hand held as usual. There is no mechanical or electronic connection between the lens and body needed to achieve this, which is why almost any non-Leica 35mm SLR lens can be used on an M240 body with an appropriate adapter. It should be noted that to fine focus you open the aperture up to maximum, if you want to zone focus you can have it stopped down to whatever, say f/8, and the focus peeking with indicator will show all the areas that are in focus, but not necessarily critically in focus as per normal zone focusing with an M lens.

 

Steve

I think the question was more around how does focus peaking kick in automatically when you turn the focus ring on an RF coupled lens, then you get the magnified portion of the image to focus on.

 

I had wondered about this too and felt it must be due to the RF cam triggering a sensor or switch.

 

Ernst

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Thanks of the explanation Steve and yes, Ernst got this right - the original question was just about how the focus aid is initialized.

 

The origin of this question for me was if there is a possibility of having this auto feature with legacy lenses.

 

Without this auto feature to me the lenses I would have seen as interesting to be used completely fail.

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As a long-time F2AS user before joining the digital brigade in 2004, I can definitely see the value in a nice 28mm or 24mm f2 (I still have an old 28mm f1.9 Vivitar original Series One in F-mount), 50mm f1.4, 85mm f1.4 and 180mm f2.8 ED AIS manual focus Nikkors would be, but I'd probably go for something more like a Sony A series full-frame camera to utilize such an outfit, not a $5,200 or more expensive Leica M body, which I bought for the rangefinder experience and using made-for rangefinder lenses that have DOF scales that are actually usable when I want to use them. I remember more than a few of those Nikkors that had DOF scales that were less than useless and distance settings that were sometimes only really accurate at infinity.

 

The six-bit coding Leica uses is better than nothing, but I have more than my share of images captured with a 6-bit coded lens that shows an incorrect aperture setting in the EXIF data.

6bit coding and aperture have absoutely NOTHING to do with each other.

 

Anyone can see that the coding is not linked to the aperture.

Edited by NB23
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Without this auto feature to me the lenses I would have seen as interesting to be used completely fail.

Rangefinder-coupled legacy lenses, including 3rd-party LTM with bayonet adapters such as my 105/2.5 Nikkor, will trigger the automatic magnification in Live View, assuming the feature is enabled.  I disabled it on mine, because even though I use the rangefinder 99% of the time, occasionally with ultra wide lenses I use the EVF instead of carrying multiple optical finders, and the forced magnification is a nuisance. 

 

For non-rangefinder coupled lenses I don't even use the manual magnification feature or peaking, as I find visual focusing through the EVF as effective as an SLR. 

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  • 2 years later...

I use a Nikon lens adapter on my M240 and fits well.  However, I notice the ISO stays at 200 and not going up until shutter speed down to 1 second.  At 1 second I can only take blurry pictures or I need a tripod.  When fit with Leica lenses, the M will try to keep lowest shutter speed at 1/45s and start jacking up the ISO. 

 

The settings are, auto shutter speed, auto ISO upper limit 3200, AWB.  Lens detection tried both ON or OFF. 

 

Lenses tested are 135 f2 ais, 75-300mm AF-D, 35-70mm AF-D all of them are having exact same behavior.  Adapter is fotodiox.

Edited by jaeger
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I use a Nikon lens adapter on my M240 and fits well.  However, I notice the ISO stays at 200 and not going up until shutter speed down to 1 second.  At 1 second I can only take blurry pictures or I need a tripod.  When fit with Leica lenses, the M will try to keep lowest shutter speed at 1/45s and start jacking up the ISO. 

 

The settings are, auto shutter speed, auto ISO upper limit 3200, AWB.  Lens detection tried both ON or OFF. 

 

Lenses tested are 135 f2 ais, 75-300mm AF-D, 35-70mm AF-D all of them are having exact same behavior.  Adapter is fotodiox.

That is because camera is not recognizing the lens (and its focal length) which is mandatory requirement for Auto ISO to work properly.

 

Simply go to auto ISO setting and set the minimum shutterspeed to a fixed value (default is based on focal length of detected or manually selected lens). After this setting, ISO value will rise once the shutterspeed hits your threshold.

 

Make sure to revert back to focal length based minimum shutterspeed for your coded Leica lens. Normally I have a profile for that which I can switch to easily.

 

Adding: If you have more than one lens that you want to regularly use then you can create corresponding profile for that lens (with specific Auto ISO minimum shutter parameter). That way you can simply switch to the profile after changing lens. Only issue is that number of profiles are limited.

Edited by jmahto
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