[RobotToaster]

You can get an identical field of view with a 30mm lens on that setup.

[blindstitch]

Same effective fov but the image will not look the same at all. The swing lens makes all areas of the frame look as if the lens is facing the subject dead on, without the same distortion that a wide produces at frame edges.

[marssaxman]

That's good to know - though the Zenzanon-S 30mm appears to be both rare and expensive enough that I'd probably count myself content with the 40mm!

[RobotToaster]

That's a shame, the soviet Zodiak-8 for Kiev/pentacon is relatively cheap, but can't be adapted to bronica AFAIK.