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Author Topic: AF adapter for Manual Focus lenses  (Read 2560 times)

EinstStein

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AF adapter for Manual Focus lenses
« on: March 07, 2016, 01:35:50 am »

An AF adapter was announced for Leica M lenses on Sony A7XX. The adapter moves the distance between the camera body and the whole lens.
This adapter can be used with any lenses as long as the lens can be adapted to M mount, which is rather easy since most lenses has longer flange distance than Leica M.
It would be particularly for MF super tele such as Nikon EDIF 600mm.

However, a recent comment from a friend about the reliability concerns with mismatched voltage/current of lenses/camera scares me away, even if the adapter uses the same voltage as the camera.
The concern is it takes a huge power to push or pull the lens from the camera body, especially if the adapter respond quick. Yes, it can be done with holding the lens so that it is actually push and pull the camera instead of the lens, but most people have the habit to hold the camera body tight against the fase or the forehead, so it will become push and pull the whole person, the implact would be horrible.

The AF adpter uses the same priciple as of the Contax/Yashica AT camera body, but it was less a problem in Contax since in that it is moving the film assembly in the camera body.

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geesbert

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Re: AF adapter for Manual Focus lenses
« Reply #1 on: March 07, 2016, 03:27:40 am »

I very much doubt that the adapter allows enough focus movement to be able to use a 600mm lens. I'd guess you would have to focus roughly and get the adapter to do the fine work
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EinstStein

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Re: AF adapter for Manual Focus lenses
« Reply #2 on: March 07, 2016, 04:57:55 am »

Of course, for super tele prefocus is a always a good common  Practice, but prefocus Would not solve the priblem. The instantaneous current to over come the lens weight or the holding pressure to keep the ca,era stable can be damaging.
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ario

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Re: AF adapter for Manual Focus lenses
« Reply #3 on: March 07, 2016, 06:48:16 am »

From Techart site:
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.

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

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Re: AF adapter for Manual Focus lenses
« Reply #4 on: March 07, 2016, 07:25:08 am »

Thanks a lot. Good to hear from real experts.
Please comment on the following usage, particularly in terms of the reliability of the adapter as well as the posible stress to the camera.

Assuming  Leica Elmar135mm F4, with left hand holding the lens while rught hand holding the camera. I believe most people will have the habit to push the lens and the camera towards the fore head. Now when the AF adapter is in charge,if it tries to oush the lens away from the camera, since the human hand will be against it more or less, it will cause moderate to severe stress to the adapter mechanically, Worse, if the adapter is smart it might try to work harder and migh cause stress to the electronic system.
Q. Any reliability test data on such situation.


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BAB

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Re: AF adapter for Manual Focus lenses
« Reply #5 on: March 07, 2016, 09:21:48 am »

Watch the Tecart newest video as he goes through several lenses and focusing situations, also pay strict attention to the details of using the adapter. For example it's said the best way to focus is wide open, and that certain focal lengths work great others not so well! My take is it's not like AF on a DSLR, but more of a work around and the lighting must be right and you must be pretty wide open?

Any user reports from actual consumers other then sites reviewers would be interesting to read!


Regards
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EinstStein

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Re: AF adapter for Manual Focus lenses
« Reply #6 on: March 07, 2016, 09:43:23 am »

Demo video can not show the reliability.
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ario

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Re: AF adapter for Manual Focus lenses
« Reply #7 on: March 07, 2016, 12:00:51 pm »

The shipping of the adapter is supposed to start end of March. I have one on order, after a few months of use I will report back about the reliability, it will be difficult before that.
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EinstStein

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Re: AF adapter for Manual Focus lenses
« Reply #8 on: March 07, 2016, 09:15:15 pm »

The shipping of the adapter is supposed to start end of March. I have one on order, after a few months of use I will report back about the reliability, it will be difficult before that.

I appreciate your joking. Hey, this is a serious question. We need the professional reliability test data.
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ario

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Re: AF adapter for Manual Focus lenses
« Reply #9 on: March 08, 2016, 09:10:53 am »

I am not joking, believe me, arguing about reliability based on actual data of something which is not yet available is difficult, at least for me. But I will try and test the adapter when it is available, I like the guinea pig role and I leave to others the privilege of being the smartest in the group.
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EinstStein

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Re: AF adapter for Manual Focus lenses
« Reply #10 on: March 08, 2016, 10:30:37 am »

I am not joking, believe me, arguing about reliability based on actual data of something which is not yet available is difficult, at least for me. But I will try and test the adapter when it is available, I like the guinea pig role and I leave to others the privilege of being the smartest in the group.

Again I appreciate your enthusiatics, and there could be people who can be satisfied by your future report.

But that's not what a professional industrial method for reliability.
Sorry.
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