[David A. Goldfarb]

This may be off-topic, but is the "compose with the front, focus with the rear" also responsible for why it is so darn difficult to do high magnification with my Mamiya RB67?

In this situation, the best approach is to set the lens and move the whole camera on a macro focusing rail. The Linhof focusing rail is sturdy enough for a medium format SLR. I've posted a photo of the rail in another thread--

http://www.apug.org/forums/forum206/...tml#post747379

This is the newest version of the rail that I've seen. There's also an older version that comes in that 70's Linhof light tan color that shows up more frequently on eBay.