Can the Techart PRO be used with any Sony mirrorless camera?
The Techart PRO has been designed to provide optimum performance with Sony cameras that support 3rd party PDAF (Phase Detection Auto Focus):

  1. Sony A7 II
  2. Sony A7R II
  3. Sony A6300
    4. Sony A9

Techart do not recommend using the TAP with cameras that are CDAF-only or whose on-sensor PDAF works only with native lenses (e.g. the A7, A7R, A7S, and A6000).

Q: Does it work with the new Sony A9 ?

A: Yes it work! Check out this youtube testing video. Link


Q: Where should I set the focusing ring when using the Techart PRO for autofocusing?

A: Normally you should park the focusing ring at INFINITY focus and use the Techart PRO for focusing.


Q: Is the 4.5mm extesion enough for my lens to autofocus for the whole focusing distance?

A: According to our testing, Techart PRO can cover the whole focusing range for lenses with 50mm focal length or below. You can simply park the focusing ring at infinty and press shutter for autofocus. For lenses with longer focal length (>50mm), users may need to coarse adjust the focusing ring to the focus point and use Techart PRO for fine focus adjustment.

    Focal Length         Focusing Range    
15mm 6.5 cm INF
21mm 12 cm  INF
24mm 15 cm  INF
28mm 20 cm  INF
35mm 31 cm  INF
50mm 60 cm  INF
90mm 1.8m INF
135mm 4.2m INF


Q: How does the focusing work and what is the difference versus focusing via the turning the focusing ring?

A: The focusing is done by adjusting the distance between the lens and focal plane (sensor). There is no difference in terms of image quality for unit focusing lenses.

Q: Is Techart PRO compatible with all Leica M lenses?

A: Techart PRO is compatible with Leica M lenses weigh under 700g.

Which autofocus features does the Techart PRO support?

  1. Focus Mode: AF-S, AF-C
  2. Focus Area: Wide, Center, Flexible Spot (S/M/L)
  3. Smile/Face Detection

Eye AF is not currently supported.

Why does the Techart PRO does not autofocus with my Sony A7 II / A7R II / A6300 camera?
The Techart PRO relies on PDAF (Phase Detection Auto Focus). Check Menu > Custom Settings (Gear Icon) > 7 > AF System and see that Phase Detection AF is selected.

Why is my Techart PRO having difficulty finding focus?
FM member GMPhotography offered a useful tip:
Remember focus is best achieved on vertical lines and not horizontal. Always look for a vertical contrast spot to get the best focus. This really is how Sonys work best.

FM member ecarlino suggested the reason for this:
The Nikon Phase-Detect module with 51 AF points has 15 points that are "cross-type sensors" to be able to detect contrast in both vertical and horizontal lines. I believe these are concentrated in the center of the frame.

I think none of the Sony On-Sensor Phase Detect AF points are "cross-type" and therefore only capable of detecting "vertical" contrast (with the camera in landscape orientation).

I am unsure of the Contrast Detect algorithm, but it's likely that it's reading row by row, left to right so it also is only detecting vertical contrast - but i haven't seen any details on that algo.

FM member k-h.a.w offered a tip for focusing fast lenses more accurately:
For shooting a fast lens, like f/1.2 or f/1.4, wide open I use AF-C and Flexible Spot: S and give it plenty of time (holding the shutter button halfway down) to focus precisely. On the A7r.2 I use IBIS and have selected Phase Detection AF and Phase Detect. Area ON.

FM admin Fred Miranda suggested a tip for using the TAP with slower lenses:
I've noticed that with slower lenses like the ZM 85/4 in low light, it's essential to keep focus on the center of the frame. It works surprisingly well as long as it stays there.

FM member rji2goleez expanded upon Fred Miranda's observation about the position of the AF focus point:
I have found this to be the case with many lenses and not necessarily slow lenses. The further to the edges of the frame the focus point is moved, the slower or more difficult it is to get AF confirmation.

FM member DavidBM confirms rji2goleez's point concerning AF acquisition with faster lenses:
Yes: sometimes very fast ones! I've noticed that the Zuiko 50mm f1.2 is more than usually sensitive to off centre focus point placement, even wide open. I'm guessing it's because the contrast drops off and aberrations increase off axis in a way that fools the focusing. Or even that the angle of incidence of the rays at very fast apertures confuses the PDAF.

Why does the Techart PRO drain my battery so quickly?
The excessive battery usage is a known issue/bug. Fred Miranda suggested a method to stop battery drainage:
Once you store your camera with TAP connected, just remove the battery and insert it back in. I have not found any drainage after doing this for a few days.
That could explain why battery drainage is not consistent and why I never found any drainage when inserting a fresh changed battery.

In a later post Fred elaborated:
If you put a fresh battery and turn the camera off, there will be no drainage.
Alternately, if you have been using the camera and turn it off, drainage will occur UNLESS you remove the battery and re-insert it.
Somehow, physically removing the battery and re-insterting it completely cuts the connection with the adapter when the camera is in "off" position.

Why don't the Techart people answer email messages promptly?
FM member DavidBM provided a credible explanation:
My experience dealing with smaller companies in China and HK is that communication beyond the selling phase is patchy at best. I don't really blame them: they have few staff, and running close to the edge, and they need to find competent English speakers to deal with issues from folks like me that don't write Chinese.

It's not customer service as some of us have come to expect. But I factor it in to my expectations. I've ordered a TechArt and am looking forward to it. But will they be around to provide service and upgrades in a few years, and will...Show more →

How does the Techart PRO affect image quality?
For unit focusing lenses (i.e. those in which the entire optical assembly moves back and forward as the focusing ring is turned), the TAP does not affect image quality. For lenses with a floating element (FLE) design (i.e. the distance between lens groups is adjusted as the lens is focused in order to improve performance at close range), the TAP will have an effect on image quality. In this case, if using the lens at close distances, it will be preferable to pre-focus manually before allowing the Techart PRO to achieve accurate focus.

FM member freaklikeme elaborates:
I'm not saying it will be particularly impactful for every shooting situation, or that every lens with an FLE will be impacted the same amount. FLEs are implemented differently. Some are like the Canon FD 85L or your Summicron 75, where the rear group remains static while the other groups move, or the Samyang TS 24/3.5, where the rear collection of groups move until about 3M when the front group also starts moving. Some are like the Touit 50 that moves multiple groups at different times in different directions. How tolerant all of those lenses are to extension tubes should vary.

Using the TAP with floating element lenses is discussed at length in this thread.

Will the Techart PRO autofocus over the full focusing range of the lens?
The autofocus range varies with the lens. According to Techart, the focusing ranges with the focus ring on the lens is set to Infinity are: 
15mm: 6.5cm > Infinity
21mm: 12cm > Infinity
24mm: 15cm > Infinity
28mm: 20cm > Infinity
35mm: 31cm > Infinity
50mm: 60cm > Infinity
90mm: 1.8m > Infinity
135mm: 4.2m > Infinity

Must the focusing ring on the lens always be set at Infinity?
No, the focusing ring on the lens can be set according to the circumstances. FM member k-h.a.w explained in this post how he divides his lenses into groups:
Normal to WA lenses, simply set the M lens to infinity, typically no pre-focusing required.
Lenses where the reach of the adapter's helicoid isn't large enough, so pre-focusing is necessary.
Special lenses, e.g. with floating elements that need to be in the right position, also require pre-focusing.
Extreme close focus, using the adapter's helicoid to achieve closer distances than possible with a rangefinder camera doesn't require pre-focusing but simply turning the M lens focus to closest distance.

How should I configure my A7 II / A7R II to switch from autofocus to manual focus and back?
Although this can be done via the (Android) configuration app, it is best to assign a Custom Button to do this. Choose Menu > Custom Settings (Gear Icon) > 7 > Custom Key Settings and assign AF/MF Ctrl Toggle to a button. FM member d-intrigue suggested using the Center Button whilst others prefer to use the AF/MF button.

The Techart PRO has a Parking feature which determines what the adapter does when switching from AF to MF mode:
  1. F36 parks the adapter at infinity focus
  2. F40 parks the adapter at closest focus
  3. F45 parks the adapter at the current focus

To implement this, set the aperture on the camera to the desired value, take a picture, then set the aperture on the camera back to F2. (Note that the camera must be set to change aperture in 1/3 stop increments for all of these options to be accessible.)

What is the heaviest lens that can be used with the Techart PRO?
According to the Techart PRO FAQ, the adapter can support lenses "as heavy as 700g". However, multiple FM members have reported success with much heavier lenses as long as the lens is supported firmly with one hand. In other words, instead of holding the camera and allowing the TAP to move the lens back and forward, one holds the lens so that the TAP moves the camera body back and forward.

Does the Techart PRO provide autofocus only with Leica M lenses?
No, other manual focus lenses with a longer flange distance (such as legacy SLR lenses) can also be auto-focused by inserting the appropriate M-mount adapter between the lens and the Techart PRO. For example, Contax C/Y or Olympus OM lenses can gain autofocus by adding a C/Y->M or OM->M adapter respectively.

Where do I buy the adapters for non-Leica M lenses?
Techart sell a wide range of Leicaist brand adapters in this store.

FM members have reported varying degrees of success with other inexpensive XX->M adapters. In order for it not to interfere with the protruding motor of the Techart PRO, the adapter needs to be quite narrow at the M-bayonet end. The Leicaist adapters are tapered to achieve this.

Do non-Leicaist XX->M adapters also work with the Techart PRO?
According to posts in the Techart PRO AF adapter now In Stock! thread some inexpensive adapters have been reported to work with the TAP. The following list shows all the adapters that are known to work.

Canon EF(EOS)

  1. Leicaist EF->M adapter

Canon FD

  1. Leicaist FD->M adapter [Note that this adapter does NOT support Canon FL-mount lenses. However, FM member bluloo has explained how the FD->M adapter can be physically modified to work with FL lenses.]

Contax C/Y

  1. Leicaist C/Y->M adapter
  2. K&F CY->M Concept adapter
  3. Fotodiox CY->M adapter

Hexanon AR

  1. Leicaist AR->M adapter

Leica R

  1. Leicaist LR->M adapter
  2. Fotodiox LR->M adapter
  3. K&F LR->M adapter
  4. Novoflex LEM/LER adapter

Minolta MD

  1. Leicaist MD->M adapter
  2. Fotodiox MD->M adapter
  3. Fotasy MD->M adapter


  1. Leicaist M42->M adapter
  2. Fotasy M42->M adapter
  3. Fotodiox M42->M adapter

Nikon F

  1. Leicaist Nikon AI->M adapter
  2. Fotodiox Nik->L/M adapter
  3. K&F Nikon AI->M Concept adapter

Nikon G

  1. Leicaist Nikon G->M adapter [FM member bluloo reports that the aperture adjustment ring "is awkward to grasp when attached to the TAP, and the throw is very short, but it's a workable solution for those with Nikon G glass."]

Olympus OM

  1. Leicaist OM->M adapter
  2. K&F Concept OM->M adapter

Pentax K

  1. Leicaist PK->M adapter
  2. Fotodiox PK->M adapter

Rollei QBM

  1. Yeenon QBM->M adapter

How do I attach the Techart PRO and lens?

  1. Turn off the camera and remove the currently mounted lens.
  2. Align the white dot on the Techart PRO with the white dot on the camera's lens mount and rotate the adapter clockwise until it locks into place.
  3. If you are using a legacy SLR lens, attach the XX->M adapter.
  4. Align the red dot on the M-mount lens (or on the XX->M adapter) with the red dot on the Techart PRO and rotate the lens (or adapted SLR lens) clockwise until it locks.
  5. Turn on the camera.
  6. Set the aperture on the camera body to F2.
  7. Set the aperture on the lens to the desired working aperture.

Can I use the Techart PRO with an L-bracket?
Various FM members have reported incompatibility with the TAP and certain L-brackets. The following L-brackets are said not to interfere with the TAP:
  1. L-bracket for Sony A7II / A7RII (USD50.00 from the Techart Store)
  2. RSS L-bracket
  3. LB-A7M2 L-bracket on eBay
  4. Neewer NW-A7M2 L-bracket on eBay
  5. A7IIL L-bracket on eBay

Does SteadyShot (IBIS) work with the Techart PRO?
Yes. There are two ways to approach this:

  1. Configure either three Custom Buttons (or, alternatively, three Function Button options) for SteadyShot Adjust (Auto/Manual), SteadyShot (On/Off), and SteadyS. Focal Len. With SteadyShot (On) and SteadyShot Adjust (Manual), you can then use SteadyS. Focal Len. to set a value from 8mm to 1000mm.
  2. Set SteadyShot Adjust to Auto and set the correct focal length to be recorded by the Techart PRO as explained later in this FAQ.

How do I update the firmware?
The Techart PRO firmware is updated via Bluetooth using a mobile phone app.

  1. Download and install the Firmware Update app using the links on the Techart Downloads page for iOS or Android.
  2. Ensure that both the phone and camera batteries are fully charged.
  3. Make sure the Auto-Lock of the phone is set to Never (iOS) or Sleep is set to 30 minutes (Android).
  4. Attach the Techart PRO adapter to the camera body (see above).
  5. Turn on the camera.
  6. Set the aperture on the camera body to F90 and take a picture.
  7. Turn the camera off.
  8. Launch the Techart Update app.
  9. Select the firmware version from the list.
  10. Press Update.
  11. Wait for the update to complete (approximately 10 minutes).
  12. When the firmware update success message appears, wait for at least one minute before turning the camera back on.
  13. You can check that the firmware has updated correctly by accessing Menu > Setup (Toolbox icon) > 6 > Version. The Techart PRO firmware version is displayed under Lens.
  14. Reset the Auto-Lock or Sleep setting on the phone.

How do I configure the focal length of the lens so it is correctly recorded in the EXIF data?
If the Techart PRO is used as shipped from the factory, a focal length of 15mm will be recorded in the EXIF. The Techart PRO can store up to ten focal lengths, with the default settings as follows.

  1. F11: 15mm
  2. F13: 18mm
  3. F14: 21mm
  4. F16: 24mm
  5. F18: 25mm
  6. F20: 28mm
  7. F22: 35mm
  8. F25: 50mm
  9. F29: 90mm
  10. F32: 135mm (MF only)

To change the focal length to be recorded in the EXIF:

  1. Check that the camera is set to change aperture in 1/3 stop increments.
  2. After switching lenses, turn on the camera.
  3. Set the aperture on the camera body to the corresponding aperture (listed above) for the desired focal length (e.g. F20 for a 28mm lens).
  4. Release the shutter (i.e. take a picture)
  5. Set the aperture on the camera body back to F2.
  6. Set the aperture on the lens to the desired working aperture.

Note that the default setting F32 for a 135mm lens switches the Techart PRO into Manual Focus mode. There seems to be general agreement amongst FM members that this was a poor choice by the Techart engineers. Firstly, because alternating between AF and MF is best achieved by setting a Custom Button on the camera for AF/MF Toggle. Secondly, because AF is just as desirable for 135mm lenses as for other focal lengths. However, this default setting for the 135mm focal length can be modified via the LM-EA7-CONFIG app.

How do I set focal lengths other than the default ones listed above?
The default focal lengths can be modified via Bluetooth using an Android mobile phone app. (Note: Currently there is no iOS version of this Configuration app.).

  1. Ensure that both the phone and camera batteries are fully charged.
  2. Download the Android APP for data settings (LM-EA7-Config.apk) from the Techart Downloads page to your Android phone.
  3. Install the LM-EA7-CONFIG app.
  4. Set the aperture on the camera body to F90 and take a picture.
  5. Turn the camera off.
  6. On the phone, go to Settings and in Display preferences set it to sleep after 10 (or 30) minutes of activity (so the display doesn't turn off during the update).
  7. Still in Settings, open the Bluetooth preferences. The LM-EA7 (i.e. the Techart PRO adapter) should be listed as an available device.
  8. Launch the LM-EA7-CONFIG app.
  9. The configuration app opens with a scrollable list of apertures, enabling you to change the focal length, parking behavior, and focus mode for up to ten lenses.
  10. Modify the default settings as desired and press CONFIG.
  11. When the configuration info has been successfully updated, turn the camera back on and set the aperture on the camera body back to F2.
  12. Test that it has worked by setting the aperture on the camera body to invoke a different focal length then take a picture.
  13. Set the aperture on the camera body back to F2, take a picture, and check the EXIF data.
  14. Reset the phone's Display settings if necessary.

Why does the EXIF data always show F2 even though I set a different maximum aperture with the LM-EA7-CONFIG app?
The EXIF will show F2 no matter what maximum aperture you have set via the config app. Fred Miranda asked the Techart people about this and they explained that, although they originally intended for the aperture value to be recorded into the EXIF via the app, they couldn't get it to work properly, so that functionality is currently blocked.

Why are my pictures overexposed when I set the aperture on the camera to a value other than F2?
When a legacy lens is attached via a dumb adapter the aperture value in the EVF on the LCD shows as "F--", because there is no electronic communication between the lens and the adapter. Correct exposure is then achieved by setting the camera to either A or M mode and using either a fixed ISO or ISO Auto.

However, in order to provide autofocus via Sony's 3rd party PDAF protocol, the Techart PRO emulates a Sony LA-EA3 adapter, in essence "pretending" to be an E-mount lens. The Techart engineers have chosen to emulate a 40mm SAM lens, probably because no such lens exists. Unlike a real A-mount lens whose aperture can be controlled electronically, the aperture on a legacy lens must be set manually. But the TAP still has to to provide an aperture value and F2 was the value chosen. Consequently, no matter what aperture is set manually on the lens, the TAP has been designed to give the correct exposure only when the aperture on the camera is set to F2. If the aperture on the camera is set, for example, to F2.8 then the camera increases the exposure to compensate and the picture will be one stop overexposed.

However, there is a way of circumventing this restriction, which is explained in the next topic.

Is there a way that I can have the actual aperture recorded in the EXIF?
FM member joe256 has reported a method of recording an aperture value (from F2 to F8) in the EXIF, whilst still exposing correctly:
Learned something new (to me at least) about the TAP. You can put the f/stop set on the lens in the EXIF (2.0 - 8.0) in addition to the focal length AND maintain the correct exposure. You do this by using exposure compensation. Set the aperture on the camera the same as on the lens, then compensate accordingly by dial or menu:
f/2.0 = 0, f/2.8 = -1, f/4.0 = -2, f/5.6 = -3, and f/8.0 = - 4 . F/8.0 has to be done in the menu while the first three can be done on the top dial or the menu. You can also interpolate. F/11 @ -5 exposes correctly and puts the aperture in the EXIF but it resets the EXIF focal length to 15mm unless you remap it via the Android app.

If you are new to TAP, note the difference between setting the f/stop set on the lens and setting it on the camera.

ADDED: If you change the exposure compensation by the menu, it resets to 0 when the camera is turned off.