Techart Pro LM-EA7 Sony A7 III

Techart Pro LM-EA7 Sony A7 III

Teachart LM-EA7 - Sony A7 III

When you work with manual objectives, but you usually use the current objectives, there are moments that are less than being able to have the quality of those lenses, but from time to time you can use the power and help in the focus of the most modern lenses and cameras. , and part of what this adapter offers us, because the Techart LM-EA7 offers the ability to use autofocus on Sony cameras that use phase detection.

But how can you get this adapter, be able to use the autofocus in the manual lenses:
In the same way that the current lenses move their lenses to focus, this adapter changes the distance between the manual lens and the camera sensor, using it the 4.5 mm that the mechanism of the adapter has to find the focus, but this is not enough, but it needs the sensor of phase detection of the Sony to allow to realize in focus, for that reason only it is compatible with the cameras that have the sensor phase detection.

But let's see the physical characteristics of this adapter:
It has a weight of 133 gr, and the first thing that stands out when we put it in the camera is that it protrudes from the bottom, this means you can not use a tripod, but this has a solution a support in L, but not all are suitable.

Another aspect to take into account is the weight limit that the adapter allows, because it only allows the assembly between the adapter and the lens does not exceed the weight of 700 gr. But this is more so that the adapter does not break, if you use a more weighty objective, provided it is balanced and the weight does not rest on the adapter, its use is possible, instead of holding the camera and allowing the adapter move the lens back and forth, one holds the lens so that the adapter moves the camera body back and forth.

But let's use it, which is what really makes this adapter special and different, with good light it focuses so fast with a native lens, but when there is little light, it is harder to focus, but this will depend largely on the camera we are using, in my case using the Sony A7 III helps a lot that the difference is not as great as in other cameras for its great help and behavior in low light use.

A negative point to highlight is the noise made by the motor to perform the focus, although it is very weak is perceptible, and this prevents it from being used in situations where no noise should be heard. We could not take advantage of the functionality offered by the Sony A7 III camera to make photos without noise.

You can review this first video about the adapter:

What the Sony A7 III gives us if we use it with this adapter:

1. Image stabilization.
2. Detection of face and eyes in the focus.
3. Use of different focus modes: center, area, flexible point, as well as focus by pressing where you want on the camera's screen.
4. You can use the AF-S and AF-C modes.

An important problem we have in the manual objectives is that by not having contacts they can not send any information, so the adapter adds a functionality to indicate to the camera the focal length that the lens has. This focal length will be configured in the adapter, so this information will reach the camera and the stabilization can be used correctly, and the EXIF ​​data of the images will have the correct focal length.

In the manuals of the adapter there is a table in which an aperture is associated with a focal length. If we modify the aperture in the camera, as it should always be at 2.0 to take the photos, the adapter takes advantage of this to indicate what type of lens we are using, so if we have a 50mm lens we will adjust the aperture of F25, we will make a photo, and then we will return the camera aperture to F2.0, from this moment the camera knows that we are using a 50mm lens.

• F11 - Adjust the focal length to 15mm
• F13 - Adjust the focal length to 18mm
• F14 - Adjust the focal length to 21mm
• F16 - Adjust the focal length to 24mm
• F18 - Adjust the focal length to 25mm
• F20 - Adjust the 28mm focal length
• F22 - Adjust the focal length to 35mm
• F25 - Adjust the focal length to 50mm
• F29 - Adjust the focal length to 90mm
• F32 - Adjust the focal length to 135mm

There are some special openings that allow us to perform other actions

F36 - E stalls the adapter in infinite focus.

F40 - Maximum extension parking adapter (closest approach)
When using this option the lens becomes fully manual and behaves like a 4.5mm extension tube that decreases the minimum focus distance on the lenses, and this allows you to take photos Closer, this is really useful in telephoto lenses.

F45 - E stalls the adapter in the current focus.

F90 - Update the firmware

The adapter allows you to update your firmware quickly and easily with a bluetooth connection and a mobile application, available for Android or Apple.

You can also download from this page an application that allows you to change the lengths assigned to the first openings of F11, F13, F14 and F16 and be able to assign the lenses we use most commonly.


Another issue of the adapter is the use of the camera's battery, because although the camera was off the adapter was still using the battery, this was solved by removing the battery and reinserting it, but this was important in cameras such as Sony A7 II that had low capacity batteries, but this problem is corrected if you use a Sony A7 III battery capacity and if you have the latest adapter firmware that turn off the adapter so you do not continue using the camera battery.

The adapter is oriented for use in photography is not recommended for videos, where manual focus will always be better.

The issue of compatibility with lenses, works best in those objectives with internal focus that extend the totality of the lenses instead of altering the arrangement of the different elements of the lens, so it is easier to work correctly with the older lenses , because the most current, usually modify internal elements.


One point that we have not seen so far is that the Techart Pro adapter is for Leica M. lenses.

Does this mean that we can only use this adapter with these types of objectives?

NO, the answer to this question is what makes it so special, because not only can we use Leica lenses but any type of mount that has an adapter for Leica. We only have to take into account that it is compatible with the adapter as we will see in the videos and the theme of the total weight of the lens assembly so as not to damage the adapter.

You can find in this video a small test with different adapters:

In the following video we can see a test done with M42 lenses so we can check the limitations of focus that we can have on more than 50mm lenses, and how we can take advantage of the adapter to take advantage of these lenses.

We added a new video with the tests with the PK-Leica adapter that in the previous video showed problems with its use, tested with new objectives the behavior has been correct, like the M42.


Sony has just released a new firmware for Sony A7III with two fundamental aspects, on the one hand the power to do timelast and take pictures automatically during a certain time range. But we will focus on the second one which is the one that most affects this adapter, the IAF or artificial intelligence in the approach, which is more than a substantial improvement in the detection of faces and eyes, but highlighting the focus in the eyes of the animals, so we made a video to see how this behavior on the Techart adapter.


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    abr 12, 2019

    Un articulo muy interesante creo que el techart me pueda ayudar a usar todas esas lentes que tengo antiguas.Gracias

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