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What Inquiring Users Want to Know


New Member
Based on threads from various internet user forums, I propose to start this off with a summary of questions that interested people are trading, that seem to yet to have no clear answers.

If anyone else actually reads this, please feel free to suggest additional or modified points to this list.

Why? Any commentary from the L-Mount partner companies would be very welcome and encouraged, even with all kinds of commitment-free disclaimers. This forum will gain a lot more attention if there is even a small indication that the manufacturers are actually engaged here! But even if no direct or immediate answers are forthcoming, it should be useful for them to know what people are asking.

Since this is a very early post in this new forum, I have no idea how much traction this will get. But it seems like this could be the right place to have visibility to the L-mount partner manufactuters.

  • What L-mount is all about
    • Is it intended to ensure full interoperability,or simply a a common mount with potentially varying operational systems of autofocus, stabilization, image pipeline etc.?
    • Is there an intent to foster, or at least not impede a high degree of adaptability to non-partner, non L-mount lenses?
    • Is the system intended to foster compatibility of accessories, batteries, flashes, connectors etc., or is it centered primarily on the lens mount alone?
  • Lens and body compatibility issues within the L-mount system:
    Assuming that there must be an internally-published L-mount specification for the partners,
    what aspects of the system are covered, are mandatory, and what are optional or flexible?
    • Mount tolerances - e.g. flange-distance, alignment, materials, strength specs
      (the first especially affects accuracy of lens infinity position and focus scale accuracy if provided)
    • Body support of various image formats and sizes, e.g. APS crop from FF, multi-aspect options and ability to create non-Leica-format (non-24x36) but "FF-sized" images.
    • Optical standards - sensor incidence & acceptance angles, spectral response of lens vs. sensor-stack, image-circle margin, minimum imaging quality standards if any
    • Unified support or allowance for image corrections (distortion, CA etc.) or any mandate prohibiting them?
    • There is a lot of concern about auto-focus systems especially contrast-detection (CDAF) as it evolves:
    • Is there any mandate or standard for the AF system, AF method or enhancements, any unified support, for AF L-mount lenses?
      • Is there any possibility for a partner to introduce Phase-detection (PDAF) as a basis or enhancement of AF within L-mount?
      • Specifically, Panasonic is already referencing ongoing developments of DFD. Is it an L-mount Alliance issue, or completely a Panasonic decision as to whether those enhancements might be supported by other bodies or other lenses?
    • Similarly for stabilization, regarding in-body (IBIS), lens optical (OIS) and combined (Dual IS):
      • Is there any position of the L-mount Alliance regarding interoperability of stabilization, particularly
        • the user's ability to choose between IBIS and OIS if both are available, and
        • support of Dual IS (by whatever trade-name) between different-manufacturer lenses and bodies?
  • Lens compatibilities outside L-mount
    • This is a very broad topic that cannot possibly be addressed in all aspects, but
    • Is it physically possible for standard L-mount to support Micro Four Thirds lenses via adapters, and if so is there any plan to make this available?
    • If not, is it contemplated that some variant or feature of an L-mount camera could be provided to enable MFT compatibility?
    • Is it the intent of the L-mount Alliance to enable adaptation of other-manufacturer APS or FF lenses?
      • Will AF and/or AE-compatible adapters be provided by partners for any non-partner lens mount?
      • Will other (current non-partners) be able to obtain a license to manufacture high-compatibility adapters for outside lens mounts?
  • Future L-mount products - without demanding obviously secret plans, the following questions are on users' minds and would at serve as input to the L-mount manufacturers. Any hints would be like gold.
    • Is there any near-term concept of a corner-EVF version of a Full-Frame L-mount camera, as in an FF Panasonic "GX" style or an FF Leica "CL" style?
    • Can users expect to see new Sigma lenses computed specifically for L-mount short-flange optimization, in addition to "mount-converted" existing lenses?
    • Can users expect to see a good range of more compact and lighter, even if slower, native L-mount lenses in the near future?


Founder of LMF
Hi Joel,

that is a very good idea!

I am in direct contact with Kazuto Yamaki (CEO of Sigma). He is a really nice person and tries very hard to fullfill the wishes of the Sigma users, both for lenses and cameras. I was really impressed about his committment and responsibility he takes over old customers. he is really committed to the photography community. I can write later on more about that.

I am also in contact with Panasonic Germany. Of course this is different than talking to the owner opf a company. More people need to get involved. More formal structures.

With Leica I will have a meeting in a few weeks, actually because of something else, but I will hold the L-Mount flag there too :)

But I can gurantee you that I will try my very best to serve the L-MOUNT community and get a positive and constructive interaction between producer and customer ;)


Founder of LMF
o.k., I see I might be able to answer some of your questions already, because soem of them were asked on Tuesday.

First let me make clear, that everything I write or somebody else writes on the internet has always to be taken with a grain of salt. The only company, which has at the moment a fully working camera and lenses is Leica.

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Both Panasonic and Sigma can tell you what they intend to do. But whether this works out in real life has to bee seen.

As an example: Look at the Partnership between Panasonic and Olympus for MicroFourThirds. I expect that it will be similar with the L-Mount alliance.

In MFT, all lenses can be used on all bodies of each brand. BUT there are feataures on some bodies or some lenses which only exist because one brand has the technology for it and a patent. This will not be shared or maybe the other brand is not interested in that.

Example. Panasonic DFD AF. Olympus uses a different system. Works with both, but the fastets sped you will have only in the combination Lumix body with Lumix lenses.

Same for Antishake etc..

So you can use both, but notb always at their full potential depending on the combination you choose.

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The flange distance is good for third party adapters. But I do not belive that Fotodiox etc. are interested to invest heavily at their own risk in adpaters with AF etc. if you see how many lenses will be avilable from one day to the other thanks to Sigma.

Sigma will offer in 2019 14 lenses with native L-mount. Plus the 6 existing Leica lenses plus 2 announced for 2019 plus 3 announced from Panasonic for 2019 alone. And in 20120 veen more will come.

So we are talking here about a very good starting position with 22 native lenses with excellent image quality and AF. In 2010 even more. I doubt that somebody wants to tale the financial risk and invst in expensive adapters, if the demand will be very low because of this great choice of native lenses from 2019 on.

BUT Sigma will offer many adapters. I will talk about that later in another thread...
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Founder of LMF
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I do not know that one...

Regarding the second group of questions:

The L-Mount is made for both, fullframe and APS-C. Leica uses the same lens mount for their cameras with the different sensor sizes and therfore this should not be a problem technically.
BUT bear in mind that Panasonic is still running their MFT line and they said clearly that they continue to invest, develop and produce new products for MFT. So the L-MOUNT is just another leg for them. Same as Canon, Nikon, Sony etc. have up to 4 different systems with different sensor sizes. This is nothing new.

I do think that the added value for only one step from MFT to APS-C is too small. I would be surprised if Panasonic or Sigma would offer anything with APS-C sized sensors. Fui for example is doing it the same way. APS-C to Medium Format. They skip the step inbetween, because they are too close to each other.

All other questions are also very good ones, but I do not have hope that at teh end of teh day this will be different tehn the cooperation fpr MFT between Panasonic and Olympus. See my point above. But In will ask that for sure.

Third group of questions:

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Panasonic told me that on Tuesday. Technicaly many things are possible. See Nikon DX automatic crop feature. But there is no plan to do so. I do not know why, but it might be an issue with Olympus. If you start to ofer an MFT->L-MOUNT aadapter, this might give the wrong signal. At least I would believe so.

MFT will stay MFT and Panasonic does not want MFT users to sell their MFt stuff in exchange for L-MOUNT cameras & lenses. That was my impression at least.

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I do think that all 3 (Leica, Panasonic and Sigma) would be happy if many users from other brands make a "soft" switch via adapters. Sigma will offer many different adapters for this. More on that later.

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If it is not on the slides I will upload later on in another thread, neither Sigma nor Panasonic will comment on future products. At least that is what they told me :)

But we can look at it from a different angle of view. If we would be Sigma and Panasonic, what would we do?

For Panasonic thi is easy. They only have MFT lenses which they can not use on the L-MOUNT. So everything from Panasonic will be specificall designed for the L-MOUNT cameras.

For Sigma it is a little more complicated. They do offere lenses for all different brands incl. Nikon and Canon. They eran a lot of money with it. So it is unlikely that they will stop this.

BUT on the other hand the have to pay no a licence fee to Leica for the use of the L-MOUNT. Leica is the owner of that mount. This is similar to the old days when Kyocera developed, designed and produced the Contax cameras, but hat to pay a licence fee to Zeiss, who is the owner of the brandname Contax.

So if you pay that money anyway, why then not start to develop also in addition new lens designs specifically for that L-MOUNT? At least I would do it.

I do think that Siga produced already so many Art lenses for other mounts, that there is not so much to do in the future. There are not so many gaps anymore in their non-L-MOUNT lens line up. So they might have now better production possibilites for new lens designs specifically for the L-MOUNT.

Great questions. I will collect more and will then try to get answers...


New Member
What would make me buy a second body to pair with my SL?

* The SL is very comfortable in my hand (I am average size for a western European, about 1.8m) but the latest mirrorless Canons and Nikons are too small. For Micro 4/3 it was OK to have a small body and grip as the lenses were lighter, but that is not the case with FF SL bodies and lenses.
* The SL has all the necessary buttons coming to my fingers when shooting.
* A joystick for moving focus point around.
* Eyepiece that tilts up and down (like the Panasonic GX7).

* Fully movable rear screen.
* Long exposures of upto 8 minutes when using ND filters at sunrise/set.

Make the electronics compatible with the electronic adaptors already available for the Leica (eg Novoflex Canon EOS, Nikon E).

Also check the SL Firmware 3.0 thread in l-camera-forum for the things that we users did and did not like about the software.


New Member
Sandokan, you mentioned the tilting EVF, a feature that I appreciate very much from the GX7 and GX8. What are your thoughts about Leica creating a corner-EVF body? It's not clear whether Panasonic would do so, at least in the first year or so of their new line.

I looked at the new CL (have had the old film CL for most of my life) but I was not ready to buy into the system as an APS-only format. I wouldn't mind having a slightly larger body in that style, or Leica Q style to get Full-Frame capability for full system entitlement, though I might still go with a couple of the smaller TL lenses for most traveling etc. A tilting EVF would be welcome if Leica would consider it.


New Member
Hi Joel,

Two things: one - I do not mind an EVF in the corner (I also shoot rangefinders): two - it does not have to be in the corner; It could be in the centre like the Fuji GFX50S.

I also did not go down the CL/T route, as I think my GX7 is still good enough for a lightweight walking or holiday camera. At least until the daughter steals it :)