What it does

Much has been made of this Leica M mount autofocus adapter for Sony since the manufacturers, Techart, announced it. The fact that you can now auto focus your M mount lenses on the Sony E mount platform is of little interest to some and downright sacrilegious to others.

However, there is a secondary purpose to this adapter in that you can also use it to auto focus manual lenses of other mounts. The short flange distance of the M mount adapter and the availability of Nikon/Canon/etc. to Leica M mount adapters makes this possible. The only limitation here is the 700g weight limit for effective autofocus. Adding another adapter here will reduce the weight limit of the lens to be attached proportionate to the weight of the additional adapter.


Objective lens mount: Leica M mount

Camera mount: Sony E

Compatible cameras: Sony A7 (II) , Sony A7R (II), A6300

Maximum bayonet extension: 4.5mm

Supported Focusing Mode: AF-S / AF-C

Aperture Control: Manual

Maximum weight supported: *700g (* Handheld support required for heavy lens)

Wireless control: Bluetooth via Android/iPhone app

Weight: 133g

Dimensions: 80 * 20 mm


The adapter is compact in size and very well made. The exterior of the unit is constructed of metal and well finished, with tight tolerances.

The problems arrive, though, when it comes to fitting it on to your camera. The housing where the motor, gearing and logic board protrudes quite drastically. In fact, when the adapter is attached, you will not be able to lay your camera down flat on its base as it protrudes at least a centimetre below the base of the camera (A7RII). This can cause some issues with mounting your camera onto a tripod, especially if your use a tripod with a quick release plate.

Additionally, if you use a case for your camera, be aware that the adapter may not fit. The gap between the mechanical housing and the camera body is around 4mm, which is less than the thickness of some cases. In my case, the thickness of my case is less than 4mm but the adapter sits in an area of reinforcement which doubles the thickness of the case and means that I had to modify the case by removing the reinforcement.

techart_img_02This is not the only area where the form factor of the adapter has caused problems. The front plate of the camera is thick and designed to fit aesthetics rather than function. It causes fitment problems when trying to mount various adapters. As far as I am aware, there are no Nikon G (aperture control), Minolta MD and Canon Eos to Leica M mount adapters available due to the front plate. Techart themselves sell a MD to M adapter themselves but at USD70 each, I am unable to verify if this works as advertised. Having access to a 3d printer, I made a slimmer mount which fits the adapter, to test the adapter on my MD lenses. It’s available for download at the bottom of this article.

It’s possible to forgive the fact that the top plate has not been tested against the various adapters available in the market. There are just too many variations with no standard dimensions. Techart themselves market this adapter as  Leica M to Sony E mount adapter and only mention that it is possible to adapt other lens mounts via adapters not mentioning which would be compatible.

However what is less in not entirely forgiveable is the fact that the top plate does a poor job of protecting the insides of the adapter. If you look at the diagram to the right the entire area outlined in orange moves in and out of the enclosure allowing the attached lens to focus. There are large gaps in the top plate which remain open and exposed. These gaps have the potential to allow both dust and moisture to enter the enclosure and cause issues with the mechanism.

I may be a little paranoid here but then again there are 2 unprotected PCBs and a motor which may be susceptible to corrosion and delicate gearing which will eventually need to be cleaned due to dust accumulation. What they have done here is compromised the design of the adapter in favour of a slimmer more compact profile. It would not have taken much more to protect the PCBs and put a cowl on the gears but to do so would result in a thicker adapter.


The first thing that you’ll notice when you use the adapter is the noise the autofocus mechanism makes. It’s by no means loud, certainly not as loud as the first generation of AF lenses or Techart’s own Contax G lens adapter (which I use on a regular basis). However, if you’re used to the current generation of AF lenses; you’ll notice it. You’ll probably not want to use this adapter for video work either. My adapter was delivered already updated Firmware v2.0, which reduced the noise output. As obvious as the noise of the motor is, it’s not annoying. The adapter sort of chirps in a polite tone.

Another consequence of the large motor is that it can drain your battery quickly. If you’re operating the adapter in conditions where it is constantly hunting, it will drain your battery quickly. I have not tested this extensively but it is noticeable. As is the fact that the adapter also drains your camera battery (slowly) if you leave it attached to your body. It is advisable to remove the adapter from the body if you do not intend to use it.

I had the chance to test it on a Sony A7RII and the A6300 and it works efficiently in both AF-S and AF-C modes, although AF-C does not work in video mode. Its speed and efficiency is dependent on how heavy the mounted lens is and how bright the conditions are. Details of my findings will be covered in the tests below.

It supports Wide, Center, Flexible Spot AF modes, Smile Detection and Face Detection. Eye-AF does not work as it’s not supported on 3rd party PDAF (Phase Detect Auto Focus).

Operation and Advanced Features

The manual from Techart is really basic. There is more Warnings, Storage, Care and Firmware Update information on the manual than on how to operate the adapter.  This is, unfortunately, the norm for Techart products. I own their EF to Nex and Contax to G adapters and, whilst I appreciate the quality and functionality of their products, their product support leaves a lot to be desired.

There is more information on Chinese language side of the dual language manual. This and trawling the Chinese language forums is the best way of getting an idea of how to make the most of their adapters.

The first thing you need to do once you’ve attached a lens to the adapter is to set the lens to focus to infinity. This is fundamental and undocumented!

Yes, you can set the lens at short of infinity but then again you’ll be spending a lot of time wondering why you can’t focus to infinity or why infinity in your shots aren’t sharp. The latter is because, if you have stopped down to the point where there is large depth of field, objects in infinity can appear to be in focus when it’s not. If you don’t calibrate the lens to infinity when the adapter is parked at infinity, then you’ll never get infinity. Depth of field will compensate for this to a degree but the effects are that you will end up with an image which looks diffracted.

I found this out the hard way because, when I first started using the adapter I had issues with certain lenses not producing consistent results. I later found out that these were caused by:

  • Accidentaly knocking the lens off its infinity position. Manual focus lenses are meant to be manually focused and therefore have prominent focusing rings. It’s not difficult to dislodge a lens point of focus off infinity and if it’s only slightly off infinity, you’ll not notice it immediately. See example below, in the first image focus is correctly set at infinity. In the second, it is just off infinity. There is enough sharpness to lock on to midrange objects (the red warning marker) but the marker itself is a little soft and infinity is just a blur.
  • The adapter was developed with ‘unit focusing’ lenses in mind. That is to say, lenses where focusing is achieved by moving entire group of elements in unison. If your lens has, what is sometimes referred to as ‘floating elements’ or ‘close range correction’ elements, you may need to re-focus manually when changing focus from far to near via the adapter or suffer some softness of image similar to the second example above. You’ll have to be aware of which of your lenses fall into this category and adjust your shooting to accommodate this.
  • Due to tolerances in mounting, some lenses can actually end up focusing past the point of infinity being in focus. Again, if this is only slightly off you’ll end up with the same issues above.
  • Some zoom lenses ‘breathe’, that is to say infinity changes when you change focal length and you need to refocus infinity each time you change focal lengths. Again, you will need to be aware of this when attempting to use zoom lenses with the adapter.

Also undocumented is the fact that, if you are using Aperture Priority mode, the in camera aperture setting has to be set to F2. Setting it at any other setting above F2 only confuse the camera metering, and cause it to overexpose. Even if you set the f stop of the lens to correspond to the aperture setting in camera.

This quirk is down to the fact that Techart uses in camera aperture settings to trigger settings on all their adapters. In the case the LM-EA7, setting the in camera aperture to F11, F13, F14, F16, F18, F20, F22, F25, F29 or F32 and taking a picture, sets subsequent pictures taken on the adapter to the set of factory defined EXIF information (see table below)

CROPMANUALENG.pdf 2016-06-03 23-22-45

Techart say that you can override the factory defined focal length information using an app which, at the time of writing (18/05/16) had not been released. I enquired on their website about the availability of this app but did not get a response.

I’m unsure why they decided to start the pre-set overrides at such a low number. F11, F16 and F22 are common aperture stops on lenses and if you were to be shooting in Manual mode and wanted to use those f stops, you will end up with inaccurate EXIF information.

The other apertures which trigger settings are:

  • F36 – which sets the adapter to the infinity position when you switch over to Manual focus mode on your camera. That is to say, if your lens is focused to infinity then when you trigger MF, it will automatically focus to infinity and you can subsequently focus accordingly using the focusing mechanism on your lens. This is the default mode and makes the most logical sense because you are effectively parking the adapter and switching over to focusing using your lens’ focusing mechanism.
  • F40 – sets the adapter to the maximum close focus distance. You can then use your lens focusing mechanism to focus even closer, effectively turning the adapter into a macro/close focus extension.
  • F45 – since firmware 2.0 was released, you can select this setting to park the adapter at the point where it is when you switch over to MF. The reason for this setting is to allow you to refine focus at the point where the adapter locks on to a subject just by switching over to MF. Use this setting if you are using a lens which is non ‘unit focusing’ or zoom lenses which ‘breathes’, it will be the quickest way of achieving focus.

techart_img_10Using the adapter for close focusing or macro work works well too. Whilst I usually prefer to use manual focusing when shooting macro, I found that using the adapter in AF-C mode allowed me to nail focus on handheld shots more often than when focusing manually. The only drawback here is that the lens weight is more crucial as gravity adds a performance hit when you are not shooting horizontally.

Setting the lens to extend to it’s fullest (F40), effectively turns the adapter into a macro extension tube and either provides or increases macro capabilities of the attached lens.

Additionally, I have had success hand holding focus bracketed macro shots using Sony’s own Bracketing app, Bracket Pro and an Open Source app FocusBracket.

Manually adjusting focus when bracket focusing often throws off image alignment. Not having to manipulate the focusing ring makes it much easier to hold the camera steady whilst bracketing.


It may seem, up to now, that I am unhappy with the adapter. Far from it, it does what it is meant to do well and lives up to its promise once you familiarize yourself with it and develop a workflow which suits you.

It’s not easy to compare the focusing speed of the Techart adapter against the autofocus mechanism of native Sony E mount lens, as the native E mount lenses only have to shuttle lightweight lens elements around internally whilst the Techart has to move the entire lens. In use, the speed of focus acquisition of the Techart adapter is dependent on the weight and how much light there is.

With lenses under 450g and in good light, the focus is acquired quickly (well under a second) and accurately. In poorer light, the adapter loses the ability to focus around 2 stops before my only native Sony lens (Sony FE 16-35mm f4) loses the same ability. I reached this conclusion by testing various lenses with adapters under 450gm against the FE 16-35mm

This is in part due to the fact that you are always focusing with the lens in stopped down mode. On native Sony lenses, the focusing in low light is done with the wide open, with the aperture kicking in with the actuation of the shutter. Additionally, the focus assist lamp kicks in under low light conditions. Neither is the case with the Techart adapter.

I have, of course tested the adapter against other lenses over 450g and here, my experience is a little bit mixed. There is a noticeable drop in performance around the 550g mark and my only test with a lens of around 700g only worked in the brightest conditions, and even then, not very well.

Speed aside, accuracy of focusing on my A7RII works remarkably well. This is the first Techart adapter I have used where there is no focus adjustment settings and it does not need it. Where it really shows it’s worth is when using fast lenses. Using the Techart adapter extends the usefulness of lenses like my Nikkor 55mm f/1.2 lens providing a lot more useful shots wide open.


Focusing in AF-C mode is equally impressive with the adapter managing to keep up with fast moving targets. In the example below, the target was moving quite quickly but the adapter managed to keep track and nail focus under low light conditions and wide open (Carl Zeiss Jenna 135mm f/3.5). In the last shot of the sequence you can see that the focus is selecting the targeted windsurfer in preference to the other surfer or the jetty in the background. This sequence and all the other example images can be found in full resolution on my Flickr album accompanying this article.


I have had the adapter for just over three weeks now and really enjoyed using it – once I got used to its quirks. If you’ve skipped to the conclusion without reading the Functionality and Operation sections of this review, I would urge you to read it. It’s lengthy for a reason. In the end, weather or not this adapter will suit your requirements will come down to whether or not the quirks I have detail put you off.

My decision to purchase the Techart adapter is based on what I intend to do with it. I have a collection of almost 100 manual focus legacy lenses, I am not averse to focusing manually.  But, with the adapter, I find that my faster lenses inherit a new degree of usability, I get more usable shots of my four year old and I can focus stack my hand held macro shots.

Additionally, I enjoy re-purposing lenses from compact film cameras and I usually modify them to be mounted on Leica M mount due to the short flange distances the lenses are focused to. Having a M mount autofocus adapter only makes it easier for me to create a focusing mechanism for the transplanted lenses.

Yes, I am frustrated by the build quality and the lack of after market Support. But then again, this is a unique product and there is no other option in the market. What it lacks in refinement, it makes up for in usefulness and delivers good results from it’s intended function.

Once you familarise yourself with the Techart adapter, it works beautifully. It provides quick and accurate focusing and extends my shooting options. And it’s also fun to use.

  • Unique functionality. It is currently the only way of auto focusing manual lenses*
  • Accurate focusing
  • Can mount lenses of most manufacturers using additional adapters
  • Compromised design, potential issues may arise from lack of protection to the internal mechanism.
  • Puts an additional hit on the battery life
  • Works best with fast lenses, performance with slower lenses can be disappointing


To address the shortcomings of the adapter, I have the following projects lined up to try and tackle the issues surfaced:
techart_img_08A better adapter cover – this was actually the first thing I tried to do when I discovered that the top cover of the adapter hampered the mounting of certain adapters. I had initial success in creating a flatter profile, 3D printed, cover for the adapter.

However, the cover is held in place with 2 1.6mm diameter screws and the torque of the focusing mechanism as it moved cause the threads for the plastic cover to wear quickly and eventually fail.

I can remedy that with a stronger, metal, brace but I need to find longer screws in order to do so. Once done I will make it available on my site for download, along with instructions.

Slim profile adapters – as mentioned in the article I created a slim profile Minolta MD to M mount adapter for my Minolta MD lenses. You can download this here. The flange distance for most of the other popular manufacturers, e.g. Pentax M42, is sufficiently long that 3rd party adapters can be mounted. Leave me a message if you find one which isn’t and I’ll try and create an adapter for it. Please note, however, that 3d printed adapters are only a temporary measure. There is no substitute for metal mounts and lens locking mechanisms and the 3d models I have created have neither.

A heavy lens cradle – it is my intention to create a cradle to help distribute the weight of heavy lenses so that the adapter can move lenses heavier than the prescribed 700g. If successful, my cradle would lessen the pressure which is exerted on the adapter mount by heavier lenses and leave only inertia to overcome.