It does exists for a very long time and without mirror
[attachment=20807:hasselblad_flex2.jpg]
And not sure the users of this kind of gear are preocupated with DoX and How much point in DR.
Yes mirror lock-up seems much more important for these kind of photographers when there is a mirror.
Oh, and by the way, does someone have ever seen a 3m size print taken with this?
I garantee that it blows your eyes from at least 30 feet far away...
but as DoX talked
[attachment=20809:dox_ceremony.jpg]
I surrender.
Best regards,
Fred.