Autofocus with Manual Lenses

Autofocus with your old Manual lenses, intrigued ? do read on. There seem to be so many arguments flying around, that it’s difficult to find head and toes in all the opinions. Most of the articles I’ve come across have a flavor of being biased; Ranging from warning concerning camera destruction, intellectual theft, to praising an adapter that working perfectly.There is two different (or identical depending on your views on intellectual theft) adapters, the Techart LM-EA7 and the Fotodiox Pro Pronto Adapter. The Pronto comes in a Sony E mount Edition and a Fuji Edition.



The helicoid adapter concept

These adapters is basically a motorized edition of the helicoid adapter concept. When you turn the focus ring of the manual lens you change the distance between the sensor and the lens. These adapters basically does the same with a motorized extension, that enables accurate movement between 0 and 4.5mm.

Autofocus and focus performance

The focus system works surprisingly well, but there is limitations to consider. The adapter relies on Phase detection, Contrast detection is not supported. This works well on my A7r3 as its phase-detect points cover around 47% of the sensor area. I easily get both face and eye focus.

I tried shooting 3 different lenses on the adapter; my Helios 40-1, which is an 85mm f/1.5 lens, Meyer-Optik Görlitz Orestor 135 mm f/ 2.8 Lens, and Carl Zeiss Jena Pancolar 50 1.8. The 50mm f/1.8 worked smoothly and accurately however it because clear that I didn’t have full range autofocus over 50mm. The 135mm and 85mm needed to be set somewhere in the proximity of focus, allowing the autofocus to work. I even had eye focus on my 85mm, but in reality, it is catching an eye whispers rather than the eye itself.

Due to the construction of the adapter is lenses with floating elements not compatible with this adapter. Luckily is floating elements very rare amount rangefinder lenses.



Odd communication  with the adapter

A thing that eluted me to begin with, was aperture setting on the camera. As there is no communication from the adapter to the aperture on the lens. Setting the f/number on the camera calibrates the stabilization and the behavior of the adapter. Setting the f/40 makes the adapter work as an extension tube, allowing for close focusing.

F11 – Set focal length to 15mm
F13 – Set focal length to 18mm
F14 – Set focal length to 21mm
F16 – Set focal length to 24mm
F18 – Set focal length to 25mm
F20 – Set focal length to 28mm
F22 – Set focal length to 35mm
F25 – Set focal length to 50mm
F29 – Set focal length to 90mm
F32 – Set focal length to 135mm
F36 – Park adapter at minimal extension (infinity)
F40 – Park adapter to maximal extension (closest focus)
F45 – Park adapter at the current extension

Build Quality

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 adapter is annoying a bit too large and protrudes at least a centimeter below the base of the camera (A7R3). This can cause some issues with mounting your camera onto a tripod, especially if you use a tripod with a quick-release plate.

Upgrade of firmware

I was also able to easily update the firmware on the Pronto Pro adapter to the latest version using the Techart app (intellectual property, which seems like a smoking gun). This improved the support for my A7r3 and cause a slight improvement in the auto-focus and the speed of the same.


This adapter features a unique functionality. as it to my knowledge is the only way of autofocusing manual lenses. The adapter provides decent to good autofocus, which can be used with success in a situation where the dynamic focus for your photography is needs (such as street photography). As a product, it could do with more product maturing, and a lot more support from the company’s part.

There are issues to overcome when using the adapter, but none of them has proven themselves to be too serious. Thus the support from TE-Chart is much better than the Fotodiox’s, then I would still buy the Fotodiox version. The Price is substantially lower, and the build quality better.

For me the adapter is a passing gadget, and will not stay with me. I think AF takes part of the charm away from using my vintage lenses, and the ability to AF is not that needed for me. On the other hand, should you value autofocus more, then I wouldn’t hesitate to purchase this adapter.



1 thought on “Autofocus with Manual Lenses

  1. MANUEL is the name of most men in Spain. Maybe you mean MANUAL focus lenses? Fixed thx

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