Question about Concept of RZ67 as a Tech-Cam

[Transposure]

Hey Guys,
Since you guys are the authority on this technical camera stuff, I thought I would ask the question here. I have been thinking about something and wanted to see if my hunch is correct. Since I own both a M645DF+ and a RZ67ProIID, I got to thinking...
The RZ67 throws a very large image circle on the film plane, large enough for the 60mmx70mm frame to fall within. The capture area of a Credo 60 or 80 is 53.9mmx40.4mm.
The RZ67 lenses are generally regarded pretty highly (at least for normal photography), although arguably not nearly as good as a Rodenstock. So, wouldn't a back plate on the RZ67 that would allow the back to shift offer a really nice technical camera alternative?
I drew a quick layout on CAD (see attached) and it seems that a Credo 60 or 80 could theoretically be shifted up to 17mm in each direction and still fall within the image circle area. Am I all wet with this?
If this is the case, it seems the design and fabrication of a stitching plate for the rear of the RZ would be a very desirable item and a very cost efficient way of having a lower cost pseudo tech cam.
I know someone is bound to say that the edges will be soft or a problem. And I do understand that. However, if you consider a standard MTF chart and realize that you could shift less than the maximum and stay away from the typically deteriorating ends of the MTF charts, you could avoid a lot of that.
In the attached CAD drawing, the yellow lines represent the RZ67 frame and assumed minimum image circle. The solid blue lines represent the Credo 60/80 capture area when hung on the existing rear adapter plate. The dashed blue lines represent a fully shifted Credo60/80 to the left. The right shifted position was not drawn to avoid confusion.
Please share your thoughts.
Thanks!
Ken

 

[Shashin]

I can't see anything wrong with your reasoning. A sifting back could work with an RZ67. However, I believe the largest format for that camera was 6x8. So you might be able to go further than your specs.

 

[ondebanks]

The later RB67 ProS and ProSD could use 6x8 backs. The RZ67 never could. The lenses are capable of it (they're mostly identical on both systems), but the rear baffle size on the RZ is the bottleneck.

 

[Transposure]

Ondebanks,
What is the "rear baffle" in your comment?

 

[ondebanks]

With no back attached, you can see the size of the rear opening on the camera. That, and the light shielding ahead of it (easier to see with the mirror up), is the rear baffle.

 

[Transposure]

Ondebanks,
Thanks. I sort of figured that, but wanted to make sure. I pulled off the adapter plate and simply moved it left and right. It appears there would be 7/16" (11mm) of shift available each way, as compared to the 17mm in my original post. Still seemingly worthwhile.
I am still waiting for the naysayers to chime in and tell me this isn't possible for reasons that I may be overlooking.
I guess the next question is (assuming this is possible) how to actually do it. Looking at the adapter plate, it has some decent thickness to it. If that was doubled (to account for a sliding plate) would the focusing be impossible or could the ground glass simply be elevated the same distance to account for the longer distance to the film/sensor plane? Making a sliding plate, replete with electronic connections and the simple DB latching mechanism wouldn't be very difficult.
Again, any thoughts? Am I missing something major?

 

[Shashin]

I guess I would try to make the sliding adapter to hold the back at the original focal plane. That would be once less piece you would need to align. You could then continue to use the camera with film backs.

 

[ondebanks]

I'd agree with Will - it's best to keep the original focal plane. Otherwise you can't focus the RZ lenses to infinity (I'm assuming that if you are making a shift system, you'd be intending to take mainly long range shots?)

If that's not possible for mechanical reasons, you could buy yourself some (7 mm) extra sliding adapter thickness by using RB lenses on the RZ body. Normally you just focus them with the viewfinder and the image lands on the same plane as the RZ lenses. But they can be racked further in by up to 7 mm, moving the focal plane backwards by the same distance (and no longer tallying with the viewfinder for focusing, unless you also raise the focusing screen by the same distance). That extra space between the back of the camera and the new focal plane might be needed for your sliding adapter.

I like your idea overall - I think it's very do-able in theory. Kapture Group did something along these lines with their stitching back adapter for the Fuji GX680: Fuji 680 digital solution

Ray

 

[Sunchai]

Hey Guys,
Since you guys are the authority on this technical camera stuff, I thought I would ask the question here. I have been thinking about something and wanted to see if my hunch is correct. Since I own both a M645DF+ and a RZ67ProIID, I got to thinking...
The RZ67 throws a very large image circle on the film plane, large enough for the 60mmx70mm frame to fall within. The capture area of a Credo 60 or 80 is 53.9mmx40.4mm.
The RZ67 lenses are generally regarded pretty highly (at least for normal photography), although arguably not nearly as good as a Rodenstock. So, wouldn't a back plate on the RZ67 that would allow the back to shift offer a really nice technical camera alternative?
I drew a quick layout on CAD (see attached) and it seems that a Credo 60 or 80 could theoretically be shifted up to 17mm in each direction and still fall within the image circle area. Am I all wet with this?
If this is the case, it seems the design and fabrication of a stitching plate for the rear of the RZ would be a very desirable item and a very cost efficient way of having a lower cost pseudo tech cam.
I know someone is bound to say that the edges will be soft or a problem. And I do understand that. However, if you consider a standard MTF chart and realize that you could shift less than the maximum and stay away from the typically deteriorating ends of the MTF charts, you could avoid a lot of that.
In the attached CAD drawing, the yellow lines represent the RZ67 frame and assumed minimum image circle. The solid blue lines represent the Credo 60/80 capture area when hung on the existing rear adapter plate. The dashed blue lines represent a fully shifted Credo60/80 to the left. The right shifted position was not drawn to avoid confusion.
Please share your thoughts.
Thanks!
Ken

Hi Ken,

Its glad to know that you have the same idea and interesting.
I have also did the studied to do the shifting adapter for RZ camera after
the RB shifting adapter was done.
But it seem to me that the distance between the image plan and the RZ body is too short as the space is less than 5 mm (in fact 3mm the thickness of Phase one adapter )the mechanical work may not be possible.
(It is too hard for me)

Therefore the idea have to change from RZ adapter to some carrier thing.
the existing RZ lens and the DF body can be put in to be able to Swing &Tilt& shifting.

Sunchai

 

[archivue]

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