HX-701 Technical Question

[Transposure]

Hi Guys,
I have a quick question.

In order to connect a Mamiya digital back to a RZ67 Pro IID, the HX-701 is required. By adding the HX-701, the digital back is assumed to be pushed an incremental distance farther back equal to the thickness of the HX-701.

I would also presume the vertical distance from the mirror center to the focusing screen is the same as the horizontal distance from the mirror center to the film plane. Therefore, what you see on the focusing screen is exactly what is projected onto the film plane once the mirror moves out of the way. Hence, allowing accurate focusing.

So, the questions....
1. Does the HX-701, in fact, push the digital back farther back?
2. If so, does the focusing screen need to be shimmed up to have the same calibrated distance to allow accurate focusing?

I would appreciate an answer from anyone with knowledge on this matter.

Thank you,
Ken

 

[yaya]

Hi Ken,

The adapter puts the sensor where the film plane is. The back was made for a 645 body, which is not as deep as the 6x7 body of the RZ. If it all fits OK then you do not need to adjust anything, however the RZ's focusing screen CAN be adjusted if required

Hope this helps

yair

 

[dougpeterson]

The location of the digital sensor when using the adapter and the location of the film emulsion when using a film back are the same.

This is because the location of the actual film in the film back was slightly recessed from the front surface of the film back. This was done knowingly to allow for use of various adapters.

In other words: focus, take a picture with a film back, remove the film back and put on a digital back (with adapter plate) and take another picture and they'll be focused in the same place*.

So it "just works". Don't overthink it .

*On a few occasions (pretty rare) we've found a back or a body which required minor adjustment to insure perfect focus parity between viewfinder and image. If working with a good dealer they can advise you on how to best test this focus parity and will help you with any minor adjustments (self or factory) prior to your purchase.