Bay 70 to 72mm step-up/down ring???

[36cm2]

Is it possible to use 72mm screw-in filters with a Bay 70 Hasselblad lens? I have adapters for my Bay 60 lenses, but I'm not sure (i) how much bigger the Bay 70s are, (ii) whether they make adapters for Bay 70 to 72mm, or (iii) whether using one would vignette the wide-angle lenses that come in Bay 70. Any help is appreciated. I've searched my usual sources for filters and rings and been unable to find a solution.

Thanks,
Leo

 

[Q.G.]

i) Bayonet 70 filters are the same size as 77 mm screw mount filters. So 72 mm would indeed be a step down.

ii) I'm not sure that there are bayonet 70 to 72 mm screw mount adapters available (you can get such step down adapters for bayonet 50 and 60, so you would think there are for bayonet 70 too).
If so, they would be third party products.

Hasselblad offered a bayonet 70 to 77 mm step up ring.

iii) There's only one wide angle lens that takes bayonet 70 filters (CFi FLE f/4 50 mm Disagon), and that lens in a previous version (CF) came with a bayonet 60 (67 mm) filter mount. The mount was enlarged because of vignetting when more than one filter was used.
So if you only put one 72 mm filter on it, there should be no problem. You can perhaps even get two, or three on without a problem.

The CFi 50 mm lens came with a bayonet 70 to bayonet 60 step down ring.

 

[36cm2]

Q.G., thanks very much, that's incredibly helpful.

 

[Q.G.]

ii) I'm not sure that there are bayonet 70 to 72 mm screw mount adapters available (you can get such step down adapters for bayonet 50 and 60, so you would think there are for bayonet 70 too).
If so, they would be third party products.

They do indeed exist: see eBay item #350363062063.

Don't know if these are any good or not.

The same seller also offer bayonet 70 to 77 mm rings: #350363062070