screw to m mount adaptor question

[peterjcb]

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I bought an adaptor for my 5cm Summitar f2 collapsible lens. It works perfectly on my MM1 and my M8.

However, when I mount it to my M6 or M3 it will not close focus. It focuses from infinity down to about 5-6 feet and stops focusing.

This happens only on my film cameras but works perfectly on my digital bodies.

 

I purchased the adaptor on eBay and it said 50  75  L39-M so I assume it should work on all 50-75mm lenses on all M mount.

Puzzled....?

[Soden]

Third party screwmount adapters are problematic at best. Most of the ones I have tried have been returned because of poor design. Part of the problem is the M (V) mount its self. It has changed over the years so that what fits easily on the old mount may not fit in the new. I have several leica adapters that fit nicely on older mounts, but a tight fit on newer gear. Another issue is the relationship between the focus wheel, focus cutaway and the focus ring/tab on the lens. This must be exact leica has used several methods for transmitting focus information. The most common is the ring. As the lens elements turns the ring moves either closer or further away. The focus wheel in the body simply follows the ring because it's on a tensioned spring. Another method is the tab. It is used on lenses like the 28 Hektor. This tab must be aligned exactly with the deapest part of the focus cutout on the adapter so it is directly over the focus wheel in the body or the focus is off. In bad cases you cannot focus to infinity.

 

In your adapter, the problem is the opposite. Remember when focusing to infinity you are bringing the lens elements closer to the media. When you are focusing closer you are moving the lens elements away from the media. Something in the adapter is preventing the focusing wheel from moving freely. That could be the focusing cutout not in the correct position because the adapter does not fit exactly. But from your description it's hard to tell.

 

What I would do, if I were certain the focus was dead on (which is unlikely per your description) is to get an old leica adapter and use that on your film cameras. Leica has made two types of adapters. One with a lock tab cutout and one without. The one with the lock tab cutout does not work with digital M's as the 6-bit code reader is exposed but will work nicely with your film M's. if you find a leica adapter with out the lock tab cutout you may use it on either digital or film M's. Another option is voightlander adapters. Good luck with cheap Chinese adapters bought on eBay.

Edited March 16, 2017 by Soden

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[peterjcb]

Third party screwmount adapters are problematic at best. Most of the ones I have tried have been returned because of poor design. Part of the problem is the M (V) mount its self. It has changed over the years so that what fits easily on the old mount may not fit in the new. I have several leica adapters that fit nicely on older mounts, but a tight fit on newer gear. Another issue is the relationship between the focus wheel, focus cutaway and the focus ring/tab on the lens. This must be exact leica has used several methods for transmitting focus information. The most common is the ring. As the lens elements turns the ring moves either closer or further away. The focus wheel in the body simply follows the ring because it's on a tensioned spring. Another method is the tab. It is used on lenses like the 28 Hektor. This tab must be aligned exactly with the deapest part of the focus cutout on the adapter so it is directly over the focus wheel in the body or the focus is off. In bad cases you cannot focus to infinity.

 

In your adapter, the problem is the opposite. Remember when focusing to infinity you are bringing the lens elements closer to the media. When you are focusing closer you are moving the lens elements away from the media. Something in the adapter is preventing the focusing wheel from moving freely. That could be the focusing cutout not in the correct position because the adapter does not fit exactly. But from your description it's hard to tell.

 

What I would do, if I were certain the focus was dead on (which is unlikely per your description) is to get an old leica adapter and use that on your film cameras. Leica has made two types of adapters. One with a lock tab cutout and one without. The one with the lock tab cutout does not work with digital M's as the 6-bit code reader is exposed but will work nicely with your film M's. if you find a leica adapter with out the lock tab cutout you may use it on either digital or film M's. Another option is voightlander adapters. Good luck with cheap Chinese adapters bought on eBay.

 

thanks for the response. I have used adaptors before and know that there are problems with generic eBay types but what puzzles me is that it works perfectly on my digital M's and doesn't work on my film M's....

as you stated, there is some problem with the rangefinder mechanism traveling. I have gone so far as to grind out a portion of the area that I believed was causing the obstruction on the adapter ring but it didn't make a difference. I still got the same results after I filed out the section...

 

...in any case, I found a Leica Original adapter 50-75 to M mount adapter used from KEH that I should receive in a day or two. I am very curious to see if this solves my dilemma. If not KEH has a 14 day guarantee that I hope NOT to use...

Edited March 16, 2017 by peterjcb

[UliWer]

_{Usually an LTM-to-M-Adaptor does not interfere with the mechanism for focussing. The problem of focussing might be caused by a lens not sitting in it's proper position because  it was not fully turned around until it "clicks". If one pushes the button to release the lense one might be able to turn it further with some slight force.  Especially the M3 has a bayonet which is  tighter than for other M-bodies, so a third party adaptor might be too "thick".}

 

_{Another remark about the lock tab cutout which you regularly find on original Leitz adaptors:}

 

_{It is true that the cutout lets open a part of the LED which read the 6-bit-code on a digital M. Though this does not make those adaptors unusable for digital cameras. For bodies without Liveview (M8, M9, M 246) it does not matter at all. If you leave lens detection on, the camera will read nothing when it sees no 6-bit-code. If you turn it off, the camera will work as well - and you do not need lens detection for a 50mm screw-mount lens. Though you can choose a manual code (e.g. for a 50mm Summicron or an Elmar-M) from the menue list of the M9 (and I am rather sure the M 246 as well). I used this for years with no problems at all.}  

 

_{When the M (240) was new there was a problem  with the adaptor's cutout - but only when you wanted to use Live-View. In the beginning LV did not work when the LED space where the code is read was not fully covered. This was changed by a firmware update: when you switch off lens-detection, you can use Live-View without problems. I am not sure about the M (240) but I tried with the M10: no problem for general use, even with Live-View when you use an adaptor which does not fully cover the 6-bit-LED. The only restriction you get is that the EVF's automatic zoom by focussing the lens does not work when the space is not fully covered by the adaptor. With an adaptor which fully covers it (they are rather rare from Leitz) the automatic zooming in the EVF works perfectly even for a lens from 1931.}

Edited March 17, 2017 by UliWer

[luigi bertolotti]

Third party screwmount adapters are problematic at best....

See this recent thread about... look at my 3 pictures with 3 different adapters on the same lens...

http://www.l-camera-forum.com/topic/270261-is-this-normal-135mm-elmar-ltm-version/

[wlaidlaw]

The lens not detected problem is still present on the M to T/L adapter. I am not sure if a firmware update for this is possible. I now have a series of LTM to M adapter rings for various purposes depending on whether or not the lens has an infinity lock, I need coding detected and want to use the lens on my SL. The nearest to well made universal LTM to M adapter rings I have come across are the Rayqual ones. The only lens that I cannot mount with a Rayqual on either the M240 or M to T/L adapter is my 5cm Hektor, where the infinity lock is in the wrong position for it to clear the cut out. As I have three Elmars, a Summitar, a Serenar and a Summicron, all in 5cm/50mm LTM, having just one lens which will not mount is no hardship. 

 

Wilson

[UliWer]

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Today i realized, that my assumption in #4 was not right...Though it was right yesterday - when I had tried in rather dark surroundings....

 

If the adaptor does not fully cover the sensor for the 6-bit-code of the M10, and your surroundings are bright enough, the sensor reacts and switches from "Manual M lens detection" to "Auto" - but cannot detect a lens. This prevents using Live View and especially to use the entry for the new 1:5.6/28mm Summaron for the old lens - which is a pity.

 

I described the issue in detail here: http://www.l-camera-forum.com/topic/268492-m10-fw-requestsbug-reports/?p=3236351.

 

It would be interesting to hear, how this works for the M (Typ 240). It is some years ago and I cannot find it anymore, though I am rather sure there was a firmware update for the M (240) which addressed the issue of uncovered 6-bit-sensors.

[peterjcb]

OK, follow up to me original question..

my issue has been resolved by purchasing an original Leica adapter ring.....my collapsible 5cm Summitar now will focus correctly on all my film and digital Leica bodies.
 

I haven't examined the original Leica adapter against the knock off yet but it was the cause of the Summitar not focusing any closer that 5 feet on my film cameras.
If anyone is having focusing issues with threaded mount to M mount adapters....my advice is get the Leica original.

[UliWer]

The lens not detected problem is still present on the M to T/L adapter. I am not sure if a firmware update for this is possible. I now have a series of LTM to M adapter rings for various purposes depending on whether or not the lens has an infinity lock, I need coding detected and want to use the lens on my SL. The nearest to well made universal LTM to M adapter rings I have come across are the Rayqual ones. The only lens that I cannot mount with a Rayqual on either the M240 or M to T/L adapter is my 5cm Hektor, where the infinity lock is in the wrong position for it to clear the cut out. As I have three Elmars, a Summitar, a Serenar and a Summicron, all in 5cm/50mm LTM, having just one lens which will not mount is no hardship. 

 

Wilson

I found the thread about the Firmware update for the M (240) which should have enabled to use screw-mount lenses better than before:

 

http://www.l-camera-forum.com/topic/229736-release-of-2015-firmware-update/

 

It says: "Live view is now possible with every lens (including older screw lenses via an adapter) using “manual lens detection”

 

Does this not work with the M (240)?

[DickieT]

I have 2 Kipon adapter rings for 28 and 35. Both work fine on my 240 and M6. No issues with focus. They cost about 35 euro

 

It is a good quality product, screw fits like a glove as well as the M fitting. The carve out is smaller than the original Leica adapters, so it allows you to code the adapter. I have simply done that with a permanent black pen, works like a charm.