[surfotog]

There have been several threads about tilt/shift lenses (or lack there of) for the 645D. There is an option that I haven't seen posted before, that's a bit roundabout and quite pricey, but thought it's worth a mention.

Zoerk offers a modified version of the Mamiya 50/4 C shift lens, with the option of tilt, shift or both. I contacted Zoerk USA about gettiing the lens in Pentax 67 mount with tilt only. This option would allow me a tilt WA for my 67, and with the addition of the Zoerk shift adapter the lens could be used as a tilt/shift with virtually any camera.
While 50mm may not be wide enough for a single shot, it could be used to stitch several frames. 50mm on a 67 is a very nice wide angle.

Zoerk USA contacted me yesterday and told me they were waiting to hear from Mr. Zoerkendorfer in Germany. I'll update this post when I get the price and delivery time.

[panoguy]

I actually saw a Hartblei 45mm PCS (shift only) lens for Pentacon Six, which could be adapted to the 645D since the image circle is big enough and the flange distance is longer, but... Russian optics! Oh well, at least there are some options out there.

[phonoline]

The guy sits in Munich, Germany. Great quality products but, boy, those prices!
I missed an auction on a Zoerk shift adapter for 67 lenses on the 645 lately. Just 700 Euros (heavily used, though).