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Auto Focus M lenses


Henry Taylor

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SInce it hasn't shipped yet, there are no practical tests on which to form an opinion.

The general principle seems fine. Focus detection from the Nikon's image sensor instructs the adapter motor to move the lens in and out to achieve max. contrast or phase alignment.

Given that this adapter moves the whole lens itself in and out - and has a limit of 4.5mm of movement - it may not be ideal with:

- Lenses using floating elements, which may not perform at their best on the adapter, except at infinity, because moving the lens in its entirety will leave the FLE in its default "infinity" setting. The light rays won't be "bent correctly" at closer distances. For best results one would need to prefocus manually to approximately the correct distance, so as to adjust the glass arrangement inside the Leica lens to be optimized for closer distances.

Similar to Hasselblad V-mount "FLE" lenses, which use a separate FLE pre-setting ring to adjust the internal optical spacing before doing the final focusing. Such lenses would include the 50 Summilux ASPH, 75 APO-Summicron, and most of the current wide-angles. Won't affect non-FLE lenses.

- Longer focal lengths (≥75mm) which likely will not autofocus to their nominal close-focus limit. For example, my handy-dandy micrometer tells me that my 75mm APO, moved forward 4.5mm, is focused at about 1.2m, instead of 0.7m. Unless, again, one "prefocuses" manually to extend the lens out from the infinity setting a bit, and then allows the AF to fine-tune the focus.

- Especially heavy lenses (50 Noctilux, 75 Noctilux/Summilux, 90 Summilux, 135 Elmarit) may be problematic to use. Depends on the power/torque of the AF drive-motor in the adapter.

- Smaller shooting apertures. AF needs a fair amount of image brightness to function at its best. Of course, we know that Leica lenses are only supposed to be shot wide-open ;) , so that may not be a significant issue.

For me, those factors mean it would be far too slow and complicated in operation for my needs. Even my Mamiya 6x6 rangefinder operates faster than I expect this would, with many lenses.

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2 hours ago, Henry Taylor said:

I would like to  know what your opinion of the new adapter now being offered for using Leica M lenses on the Nikon Z's . I believe its being sold under the name Techart

The responses have already been quite comprehensive, so I won’t go over covered ground. 

My desire for an adapter like this is to have “in focus” shots in the following condition:

-subject is moving or can’t stand still

-I want “bokeh” —>  lens wide open 

My situation: I have a fairly active infant and the adapter fulfils my requirement above  

the issues/constraints:

-battery consumption increases (to power motor)

-battery drain (slightly)

-the techart has an issue where it may “wobble” if the adapter has been used outside of the specification (assumption: no design changes from the Sony version)

-Autofocus performance is not like native lenses (but still acceptable in my opinion)

-exif data / adapter doesn’t read 6 bit coding 

-focal lengths greater than 100mm (refer to the other thread)

-weight limits 

-[risk] new camera firmware update may cause issues with adapter (reference: breakages caused by firmware 1.20 on A7riv) 

My experiences 

Great. As the adapters uses the Leica M mount, I have other options of adapting my other lenses (I.e canon FD, Nikon, Konica, M42, LTM etc). So it has “modernised” a lot of my lenses.. it’s worth every penny in my opinion

Reviews/Product demo:

-Leica 50mm 0.95 Noc (Note: Sony) - 

 

-Nikon Z megadap review (pros/cons)

 

 

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Back in 1996 Contax utilized a system on their 35mm AX slr model to autofocus mostly Zeiss and Yashica manual focus lenses, except their process moved the film plane rather than the lens. In their case one had to somewhat prefocus the lens before utilizing the autofocus mechanism for final focus adjustment. I wonder if similar methodology might improve the versatility of the Techart system.

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I've got the version for my Sony A7II. It works fine. It's not incredibly fast, but quick enough and it's pretty reliable.

But I would not like to use very heavy lenses adapted to it, since the internal helicoid mechanics might be a little too fragile for long tele lenses.
(You could adapt R lenses to M and then use those SLR lenses on the TechArt adapter.)

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On 11/22/2020 at 8:27 PM, adan said:

SInce it hasn't shipped yet, there are no practical tests on which to form an opinion.

Actually this is a revised version of the Sony adapter, so plenty of reviews and practical tests available :-)

I have one and I've been happily using it on my A7rIV for a few years now.

AF is quick enough in the center area and initial midzone, starts to struggle when you move the focus point from the midzone toward the edges, it won't focus at the extreme edges. It also struggle in low light. But it works great if you work within its limitations. Accurate eye-af at 1.4 ;-)

Yes, it won't work well with lenses with floating elements. I still use my 50 Lux wide open for portraits though, and can't complain about the results.

Regarding smaller apertures, it's not a problem. I use this adapter all the time with an Elmarit M 2.8 and stopped down to F8 or more, and never had any issue. I don't know about the MFD, I never noticed it.

Heavy lenses above 600g are not recommended by the manufacturer. The Sony version has a design flaw and after continuos use with heavy lenses, the adapter will develop a "wobble" that affects image quality.

Apparently this last issue is resolved in the Nikon version.

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52 minutes ago, Simone_DF said:

I have one and I've been happily using it on my A7rIV for a few years now.

Hi @Simone_DF, can I just confirm that the adapter functions well on the A7riv running on the latest firmware (at time of writing v1.20)? 

As there have been conflicting reports where the latest firmware has issues with the adapter (won’t AF), additionally can I confirm what brand is your adapter ?(techart pro?) 

thanks. 

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37 minutes ago, Raymondl said:

Hi @Simone_DF, can I just confirm that the adapter functions well on the A7riv running on the latest firmware (at time of writing v1.20)? 

As there have been conflicting reports where the latest firmware has issues with the adapter (won’t AF), additionally can I confirm what brand is your adapter ?(techart pro?) 

thanks. 

Hi Raymond, I just checked and it appears I'm still on firmware v1.1, I didn't even know... :ph34r:

It looks like the 1.2 update addresses only an issue with video. I won't update mine.

Yes, I have a Techart pro.

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16 minutes ago, Simone_DF said:

Hi Raymond, I just checked and it appears I'm still on firmware v1.1, I didn't even know... :ph34r:

It looks like the 1.2 update addresses only an issue with video. I won't update mine.

Yes, I have a Techart pro.

Yes from what I have read/followed the V1.20 (A7riv) introduces support for the Sony adapter LA-E5 will render the techart pro “useless” on the A7riv as autofocus will cease to function. I suspect there is a conflict somewhere... hope techart releases a fix soon... 

thanks for the clarification. 

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1 minute ago, Raymondl said:

Yes from what I have read/followed the V1.20 (A7riv) introduces support for the Sony adapter LA-E5 will render the techart pro “useless” on the A7riv as autofocus will cease to function. I suspect there is a conflict somewhere... hope techart releases a fix soon... 

thanks for the clarification. 

They will. Techart released many firmware updates to improve compatibility since the first version. As soon as they find a fix, they'll patch the firmware, also because I assume the adapter LA-E5 support will be baked in in all future Sony cameras.

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10 hours ago, jdlaing said:

Me neither. It’s blasphemy.

I wonder if there's something you tolerate in this world :P

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Simply register for free here – We are always happy to welcome new members!

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You guys should be glad these autofocus adapters exists. It means Leica will sell more lenses to non-Leica users and make more profits to develop the cameras and lenses we all love.

And probably one of these users, every now and then, will also try a Leica camera.

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1 hour ago, Simone_DF said:

It means Leica will sell more lenses to non-Leica users and make more profits to develop the cameras and lenses we all love.

That I doubt very much.

 

No one is going to buy a Leica lens and then stick it onto an adapter to kludge autofocus, when they can just buy a native mount autofocus lens from the camera manufacturer or a third party lens specialist.

 

These things are for people who already own Leica M lenses who want to use them on an alternative mount AND want autofocus as well. Given that this doesn't solve the need to stop the lens down manually, I would have thought that the market was very small indeed. M users are (obviously) used to manually focusing.

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