RB67 PRO SD and 6x8 back question

[rmann]

I am confused, If a have a RB67 Pro SD camera body and want to add the 6x8 film back -
Will it work with the SD revolving back, or do I need a special 6x8 revolving back?

 

[WilmarcoImaging]

According to this: https://rb67.helluin.org/backs/, all backs, bodies and revolving adapters are interchangeable, the difference is the image size achievable. For maximum image size a Pro-SD body, Pro-SD revolving adapter and 6x8 back are needed.

 

[rmann]

According to this: https://rb67.helluin.org/backs/, all backs, bodies and revolving adapters are interchangeable, the difference is the image size achievable. For maximum image size a Pro-SD body, Pro-SD revolving adapter and 6x8 back are needed.

Thanks, so the special 6x8 revolving back is for earlier models, and an SD is ready for a 6x8 back.

 

[EdSawyer]

6x8 is optimistic, it's really 72 or 74mm in the long direction, at most.

 

[alanrockwood]

6x8 is optimistic, it's really 72 or 74mm in the long direction, at most.

How does this dimension compare with a regular 6x7 centimeter back?

 

[Neil Grant]

6x8 is optimistic, it's really 72 or 74mm in the long direction, at most.

... 6x8 cm is just nominal. Typically it would measure 56x76mm. The RB body can't quite deliver that, maybe 56x75mm at most - but this does depend on the lens in use. (wider lenses cover more - the 37mm fisheye even shows the petal hood in the corners)
The correct 6x8 revolving adaptor and '8' body baffle are needed, these being standard fit on the very last RB Pro S models and all Pro SD. If your body has the wrong baffle you can easily unscrew it for the proper one or, if this cannot be obtained, enlarge the opening in the one you have.

 

[rmann]

[QUOTE="
The correct 6x8 revolving adaptor and '8' body baffle are needed, these being standard fit on the very last RB Pro S models and all Pro SD. If your body has the wrong baffle you can easily unscrew it for the proper one or, if this cannot be obtained, enlarge the opening in the one you have.[/QUOTE]

Thanks, this is exactly what I was trying to determine.

 

[WilmarcoImaging]

From the helluin site, image sizes:

• Normal RB67: 5.6cm x 6.8cm negative.
• RB67 Pro Body + RB67 Pro revolving adapter + 6×8 power back: 5.6cm x 7.2cm negative.
• RB67 Pro Body + RB67 Pro-SD revolving adapter + 6×8 power back: 5.6cm x 7.3cm negative
• RB67 Pro Body + RB67 Pro-SD revolving adapter+ 6×8 power back + “8” light baffle: 5.6cm x 7.5cm negative

There is no image size given on the site for "full 6x8" setup. The above are for less-than-full-6x8 setups. However, the last entry above seems like it is the answer. Does the body itself restrict image size, or is it only the revolving adapter and film back that are the restrictions?