Could Actus or Universalis be improved with full electronic integration to A7 ?

[marc aurel]

The Canon lens panels for Cambo Actus and Arca Universalis seem to be a great new tool for those who want to use it with mirrorless cameras like the A7 series cameras.

The advantages have been discussed in other threads:
•   you can use the Canon TS-Es with a more traditional view camera handling
•   you can also use zoom lenses like the 11-24mm or the 16-35mm f4 which – like Stefan Steib and his HCam TS adapter have shown – have astonishing reserves for shifting.
•   you can combine Canon lenses and other lenses on the same camera platform

The disadvantages for me are:
•   there is no electronic integration between lens and camera – like you have it with a metabones adapter
•   setting the aperture and changing between wide open and set aperture (for focusing) is not as simple – although the new electronic lens panels by Cambo and Arca mostly solve that
•   exif data is not recorded. That makes it difficult to correct the files for distortion – especially with the zoom lenses. If you don’t know the focal length of a shot taken with a zoom lens that was shifted additionally – does not sound like fun to me.

I would love if it was possible to improve that. I don’t have the tools and the knowledge to do such a project, but I would like to propose this idea. Maybe there are more knowledgable people who like it.

I took apart a Metabones III adpater (EF to E-Mount). The electronic board and the electronic contacts are quite small and can easily be taken out. My idea would be to:
•   attach the part with lens contacts for E-mount to the camera mount of the Actus or Universalis
•   attach the metabones main board with the ef lens contacts to a the lens board (Cambo even offers a „mechanical“ lens board for Canon, the ACB-CM, which you could use).
•   the cable connection is definitely too short, you would have to disconnect, add longer cables and a plug connection

Of course there are problems:
•   How could the cables be lead inside the bellows so that they can not block the optical path? Or is it possible to move the cables outside the bellows without letting light in?
•   To be able to use the push button of the metabones adapter (for wide open mode) you would have to add another cable, lead it outside the bellows and add an external button.

If that would work – maybe you could even add a Jasring adapter (Contax 645 to Canon Eos) and use the Contax 645 lenses on an A7RII with movements and full electronic integration.

What do you think? Would that be doable?

[Theodoros]

All that you need on a view camera is to be able to control the aperture of the lenses that have electronic aperture control... AF, modes and all other features are completely useless... The way I would then do it, would be to buy an old S/H NEX-5 or NEX -3 body, buy a cheaper adapter than the metabones too and just make a lens board by using the Sony NEX electronics (and battery) in series with the adapter's ones...

If you however insist to control the aperture from the α7 body, Just take apart the adapter, use the Camera mount of it on the rear standard and the lens mount of it on the front standard, buy a flex cable with enough cables in it for the number of pins, then attach the electronic PCE board of the adapter to the frame of the front standard, reconnect the CPU pins of it to the PCE board and then connect the flex cable to the PCE board from one side and to the camera mount CPU pins on the other side. It will work... 

[alan_b]

Chiek did it with a Sinar: http://forum.luminous-landscape.com/index.php?topic=104066.0

[marc aurel]

Thanks, Alan and Theodorus.
I didn't know Chiek already did this with the Sinar. Really quite impressive. Must really have been a lot of work. I guess that with Cambo or Universalis it would not afford as much milling and drilling because they already offer the necessary mounts. So the main task would be to reaorganise the electronics, add cables and plug connections and attach that to the mounts. But probably still a lot of work.
I will definitely have a look at the details of how arca implemented the electronic canon lens board before I start this...

Regards -
Marc

[Theodoros]

Thanks, Alan and Theodorus.
I didn't know Chiek already did this with the Sinar. Really quite impressive. Must really have been a lot of work. I guess that with Cambo or Universalis it would not afford as much milling and drilling because they already offer the necessary mounts. So the main task would be to reaorganise the electronics, add cables and plug connections and attach that to the mounts. But probably still a lot of work.
I will definitely have a look at the details of how arca implemented the electronic canon lens board before I start this...

Regards -
Marc

Mark... The Sinar P series is very easy to convert, you will have to make new front and rear frames, but that will be all because the frames of the camera are very easy to remove. I'm working on converting a Sinar P now (after I finished with the Rollei X-Act 2) and I must say, other than the weight it is the most reliable solution...

The conversion I do, is to use front frame of 85mm internal diameter disk (95mm outside diameter) and then 72mm internal diameter disk (82mm on the outside diameter) for the rear frame. Both disks have "L" shaped base where the height 6.5mm different (so that the the circle centre of both is aligned),  the base of the "L" is sliding in an Arca Swiss type of mount which is fitted where the Sinar frames used to be... I made the frames sliding so that I can position the entrance pupil of the lens and the centre of the sensor as to be exactly where they should be, so that there is no distortion when tilting or swinging...

The front frame (the 85mm diameter one) will allow for one to use the massive collection of the NOVOFLEX BALPRO lens boards, which are quite reasonably priced and very well made too... The rear 72mm diameter, will allow for one to recess the grip of the Sony so that he won't loose any space because of it. Only thing that is then left, is for you to take apart a Canon to Sony a adapter, put the front mount (the Canon on a Balpro lens board), glue the electronics of the adapter on the frame of the board, and then mount the Sony mount of the adapter on a disk of 72mm diameter and mount it on the rear frame and then, just connect the two via a flex cable... For bellows, I've made my own, but you can easily convert any S/H one out of a Fuji GX 680 or any 6x9 view camera. Not only it will work, but one can use the rest of the Balpro lens board and mount other lenses than Canon on it...

If you want me to sent you the drawings of mine, don't hesitate to ask...  I'm sure it would cost you much less than you thing in any machinist's lab in the world...  You'll love it I'm sure...

P.S: On the rear standard one can use an MFDB (and a sliding Kapture group VF too...) as well by just removing the Sony and attaching the MFDB... There is only 27mm between the Sony and the lens board, so there is plenty of working space even if the lens is of 35mm DSLR mounting distance...

[marc aurel]

Mark... The Sinar P series is very easy to convert, you will have to make new front and rear frames, but that will be all because the frames of the camera are very easy to remove. I'm working on converting a Sinar P now (after I finished with the Rollei X-Act 2) and I must say, other than the weight it is the most reliable solution...

Thanks, Theodoros.
The Sinar would be a bit too heavy for me. I mostly photograph architecture, so I have to carry it around a lot. At the moment I tend towards the Arca F-Universalis.
Marc