A big 'thumb up' for the Arca-Swiss' R&D team

[SwissBear]

I would like to send a big 'thumb up' for the Arca-Swiss' R&D team (a one man show named Julien) for the development of special lens plates...

Following Rob's advice and guidance, I have ordered an F-Universalis some weeks ago. I have, at the time of order, requested a special lens plate to mount Mamiya RZ67 lenses on my view camera, as well as a lens plate to accommodate the Laowa 20mm T/S.

In the interval, Rob has finished to specify his Mamiya N lenses plate and I have asked Julien if he could build one for me based on the Rob's document.

Everything was delivered yesterday. And everything was realised with the utmost professionalism and quality of execution. I would very warmly recommend Arca-Swiss for being able to deliver special projects, due to their flexibility and quality of work.

And thanks again to Rob for his recommendation and Mamiya N lens plate specification.

A quick picture of the camera:


Here are a few pictures of those lens plates:
The Laowa:


The Mamiya N lens plate:


The Mamiya RZ67 lens plate:

 

[Paul Spinnler]

Amazing - I will reach out for a S adapter. Arca is unique in the sense that they have an integrated CNC dept. courtesy of the boat load of heads they are producing. It gives them an advantage for these things.

 

[Vilpo]

Is that lever on RZ67 lens plate for a leaf shutter or for aperture control, or just for lens attachment to the plate?

 

[SwissBear]

Is that lever on RZ67 lens plate for a leaf shutter or for aperture control, or just for lens attachment to the plate?

It's to activate the shutter cocking. Using the "T" position on the lens allows you to have an appropriate aperture, but Arca-Swiss provided with a simpler way to force the lens to close to the selected aperture using a simple adhesive metal plate to keep the aperture lever of the lens closed.

 

[rdeloe]

Pierre, I'm so happy for you! Those boards look fantastic. They did an amazing job.

I hope you get a lot of use and enjoyment out of what is now an extremely flexible system. We are all looking forward to hearing about how all the bits and pieces work.

 

[SwissBear]

Pierre, I'm so happy for you! Those boards look fantastic. They did an amazing job.

I hope you get a lot of use and enjoyment out of what is now an extremely flexible system. We are all looking forward to hearing about how all the bits and pieces work.

Thank you Rob. I will certainly share my findings as I move forward on the learning curve. One thing is absolutely clear in my mind and that is that this small Apo-Componon shown above is an outstanding lens. It's sharp from center to borders and does not show distorsions. Impressive.

I had the opportunity to test the Pentax 35mm and 75mm during my evaluation of the Cambo Actus. They are confirming their promises in this new setup, with the limitation of their image circles which are large but not immense, and on the samples I have, there is a clear softness when shifted (15mm). Nothing unacceptable.

A good surprise for me is the 127mm Mamiya RZ67 (K/L version). It is surprisingly sharp, with a great image circle, and does much better on the view camera than on the Fotodiox adapter. Same for the Laowa 20mm, which does better in this configuration compared to the GFX mount I had.

I noticed that the Mamiya RZ67 lens plate will need to be further adapted for lenses with electronic contacts. I will be in touch with Julien on this one.

 

[SwissBear]

Amazing - I will reach out for a S adapter. Arca is unique in the sense that they have an integrated CNC dept. courtesy of the boat load of heads they are producing. It gives them an advantage for these things.

Please be aware that manufacturing a special lens plate can be very expensive. The lens plates they built for me are based on an adapter they found on the market for the Mamiya RZ67 and an extension tube Rob had suggested for the Mamiya N lenses. In case they need to develop a special mount for you, outside of an existing adapter, this will probably be a whole project, with significant time and costs involved.

 

[Paul Spinnler]

Please be aware that manufacturing a special lens plate can be very expensive. The lens plates they built for me are based on an adapter they found on the market for the Mamiya RZ67 and an extension tube Rob had suggested for the Mamiya N lenses. In case they need to develop a special mount for you, outside of an existing adapter, this will probably be a whole project, with significant time and costs involved.

I am aware of this. You can sacrifice the mount in the existing s gfx adapter (cheap solution) or kill the S to SL adapter. With arca I wanted to kill the S to gfx adapter

 

[observedlight]

Woah, just saw this thread now. What timing as I was interested in ordering the universalis but only have existing RZ lenses. No large format lenses.

Rob in another thread mentioned the lenses wasn't obviously designed for this setup...

How much shift are you getting with the RZ lens and the medium format image circle?
I also thought the RZ leneses weren't mechanical, so do you need arca swiss to build a plate with electronic contacts before you can use them specifically?

 

[Paul Spinnler]

My experience with P67's Takumar 105 2.4 on Alpa indicates 18mm left / right no problem in portrait position, just a hint of vignetting. P67 has some affordable super teles ... RZ should be similar with the longer focal lengths affording more IC than the wider ones. I'd assume anything above 100mm will give you great IC with low to no vignetting.

 

[SwissBear]

Woah, just saw this thread now. What timing as I was interested in ordering the universalis but only have existing RZ lenses. No large format lenses.

Rob in another thread mentioned the lenses wasn't obviously designed for this setup...

How much shift are you getting with the RZ lens and the medium format image circle?
I also thought the RZ leneses weren't mechanical, so do you need arca swiss to build a plate with electronic contacts before you can use them specifically?

Glad you like it.
With my "small" sensor (33x44mm) in vertical position, and my 127mm lens, I can use the maximal shift available for the F-Universalis, which is 25mm on each side.
If you do the math, you will notice that this 44x83mm image has a diagonal which is only slightly larger than the original 56x69mm of the RZ67.

 

[rdeloe]

Woah, just saw this thread now. What timing as I was interested in ordering the universalis but only have existing RZ lenses. No large format lenses.

Have you seen my 'working review' of the F-Universalis? It's in the form of a PDF: https://drive.google.com/file/d/1R0qfcYfwAEUlJ8LG8GyaCE-7W3Ac3lh3/view?usp=share_link

Rob in another thread mentioned the lenses wasn't obviously designed for this setup...

How much shift are you getting with the RZ lens and the medium format image circle?
I also thought the RZ leneses weren't mechanical, so do you need arca swiss to build a plate with electronic contacts before you can use them specifically?

The problem I was hinting at in that other thread is that knowing the size of the image circle alone may not be enough due to mechanical reasons. For example, I have a Pentax 67 200mm f/4 lens that I thought I would use with a Fotodiox Tilt ROKR adapter. It's much too heavy for any digital view camera (like an Arca Swiss), but would have worked fine with the Fotodiox because I have it on a custom collar. Anyway, it's a P67 lens and it's a tele lens so the image circle should be large and give me plenty of shift room. Alas, that's not the case. Is it the design of the lens? Is it the Pentax 67 to 645 adapter I use to connect to the Fotodiox? Or is it the Fotodiox adapter design? Or all of the above? Whatever the reason, when I shift 12mm left and right with this setup, I get hard mechanical vignetting on both sides.



Another consideration with using mirrorless cameras on F-Universalis or Cambo Actus outfits that relates to how much shift you can get is the fact that the sensor is inside a cavity (as opposed to being on the surface as with a medium format back). With a GFX camera, mechanical vignetting from the upper edge of the sensor "cavity" happens long before you run out of image circle with some lenses. With my Mamiya N 65mm f/4.5, I have this problem at 20mm. I have other lenses with different designs that allow 30mm of shift, but any more than that and there's mechanical vignetting from the edge of the sensor cavity blocking the light.

I haven't used RZ lenses, but the system has a long flange distance and the rear elements don't project past the mount. Those are optimal conditions (usually) for getting maximum shift. My Pentax 67 200mm is a notable exception -- but remember, it's not on an F-Universalis in these pictures.

 

[RodK]

I think you have diagnosed correctly, that the 6x7 to 645 adapter may be causing the mechanical vignetting.

Good job.

Rod

 

[Paul Spinnler]

The Alpa adapter didn’t produce any mechanical vignetting on the Takumar 105 shifted fully left right on the STC.

I think it is the adapter. The Alpa one is wide directly after the adapter ring.

 

[observedlight]

Have you seen my 'working review' of the F-Universalis? It's in the form of a PDF: https://drive.google.com/file/d/1R0qfcYfwAEUlJ8LG8GyaCE-7W3Ac3lh3/view?usp=share_link



The problem I was hinting at in that other thread is that knowing the size of the image circle alone may not be enough due to mechanical reasons. For example, I have a Pentax 67 200mm f/4 lens that I thought I would use with a Fotodiox Tilt ROKR adapter. It's much too heavy for any digital view camera (like an Arca Swiss), but would have worked fine with the Fotodiox because I have it on a custom collar. Anyway, it's a P67 lens and it's a tele lens so the image circle should be large and give me plenty of shift room. Alas, that's not the case. Is it the design of the lens? Is it the Pentax 67 to 645 adapter I use to connect to the Fotodiox? Or is it the Fotodiox adapter design? Or all of the above? Whatever the reason, when I shift 12mm left and right with this setup, I get hard mechanical vignetting on both sides.

View attachment 201909

Another consideration with using mirrorless cameras on F-Universalis or Cambo Actus outfits that relates to how much shift you can get is the fact that the sensor is inside a cavity (as opposed to being on the surface as with a medium format back). With a GFX camera, mechanical vignetting from the upper edge of the sensor "cavity" happens long before you run out of image circle with some lenses. With my Mamiya N 65mm f/4.5, I have this problem at 20mm. I have other lenses with different designs that allow 30mm of shift, but any more than that and there's mechanical vignetting from the edge of the sensor cavity blocking the light.

I haven't used RZ lenses, but the system has a long flange distance and the rear elements don't project past the mount. Those are optimal conditions (usually) for getting maximum shift. My Pentax 67 200mm is a notable exception -- but remember, it's not on an F-Universalis in these pictures.

Thanks Rob. Makes sense. One thing i was looking to eliminste, I was thinking of the hassy cfv ii 50 digital back rather than a gfx body as I'd assume that would allow for more movement straight off the bat.

I see that cambo had an hour long webinar on this setup with hassy on YouTube 2 yes ago, which I'll watch.

They were using the cambo WS system instead though which they weren't using bellows like the univeralis or actus g. So much to learn!

 

[rdeloe]

The Alpa adapter didn’t produce any mechanical vignetting on the Takumar 105 shifted fully left right on the STC.

I think it is the adapter. The Alpa one is wide directly after the adapter ring.

Paul and Rod: So now you made me curious enough to figure it out. I hadn't bothered before because the lens is too heavy for my F-Universalis, so it went straight into the "drawer of stuff I need to sell".

Anyway, long story short, it's the Fotodiox Tilt ROKR. It doesn't play nice with this lens and the P67 to P645 adapter. When I mount the P67 200/4 on my Arca Swiss Pentax 645 board, I can shift 25 mm before mechanical vignetting starts.

It's just one of those things. It's a long tele so the rear element is deep inside the body of the lens. That plus the extension from the P67 to P645 adapter plus the shape of the Fotodiox Tilt ROKR produces a combo that doesn't work.

 

[rdeloe]

Thanks Rob. Makes sense. One thing i was looking to eliminste, I was thinking of the hassy cfv ii 50 digital back rather than a gfx body as I'd assume that would allow for more movement straight off the bat.

I see that cambo had an hour long webinar on this setup with hassy on YouTube 2 yes ago, which I'll watch.

They were using the cambo WS system instead though which they weren't using bellows like the univeralis or actus g. So much to learn!

Whether you get more movement with the CFV II 50 depends on the lens. The sensor has to be in exactly the same spot for every lens you use as it does for any other camera (regardless of format). What the CFV II 50 (and similar medium format back designs) do for you is eliminate mechanical obstructions. On a GFX camera (or any other mirrorless), the sensor is deep inside the body and there's a lens mount to contend with.

In a nutshell, you might get more shift capability with the CFV II 50 in a couple cases:

1. You're in a situation where the limitation on shift is the opening that leads to the sensor (as is the case on my GFX 50R).
2. You're using a lens with a short flange distance, and especially if the rear of the lens sticks out past the flange.

A case in point for #2 is my new addition to the lens lineup: the Mamiya N 43mm f/4.5 L. What a stellar lens that is, but it has a huge rear end that goes all the way through the Rotafoot on my F-Universalis and actually pokes a bit into the body of the GFX camera. The rear lens is around 50mm outer diameter, which means I get a max of around 5mm of left-right-up-down movement. For what I do, that's enough to make it worth carrying this fantastic lens. If I were using a CFV II 50, I'd be able to shift right to the edge of the circle of good definition, because the rear of the lens would clear the rear standard.

 

[LonnaTucker]

Observedlight,

Rob is correct above, but I would add that the greatest advantage of a digital back over a mirrorless camera is the full range of wide angle technical lenses can be utilized.

Also, the view camera can move freely without mirrorless camera grip interference.

 

[observedlight]

Thank you both! I might start a new thread though as I feel like this is hijacking the OPs. Still had a few Q's