I can think of 2 "technical" reasons why the mechanical coupling was not employed in *istD & *istDS.
1) Due to the unique design of the inner chassis (basically a few metal sheets screwed together), there is no space for the coupling ring because the lens mount was tightened onto the front metal sheet direct. Unlike the old die cast structure which can afford the extra space for the coupling ring, adding this mechanical ring between the metal sheet and the camera mount is possible, but it is going to add more than just the ring itself, but a whole new structure in between as well. This will increase the manufacturing cost significantly, as well as weakening the link between the camera and heavy lenses.
2) For the same reason, there is no space for the aperture resistor required for the mechanical coupling (takes too much space underneath the Pentax logo). So there is actual technical reasons to omit this beloved design which we have relied on for so many years, or at least I believe so.
Alan Chan http://www.pbase.com/wlachan
Paul you know advertising/marketing, do you really truly think that dropping the compatibility was more than a sales tools? There really is NO SOUND TECHNICAL REASON for its exclusion...
My emphasis, above...
So far as you know, you mean. Unless you sat in on production engineering meetings that approved all changes before the final design was complete, how can you possibly that? I suggest you don't. All these hard and fast pronouncements of "fact" are little more then educated suppositions. Good ones, but... Might be true, right? Then again, might not... hmmm.
_________________________________________________________________
Designer Mail isn't just fun to send, it's fun to receive. Use special stationery, fonts and colors. http://join.msn.com/?pgmarket=en-ca&page=byoa/prem&xAPID=1994&DI=1034&SU=http://hotmail.com/enca&HL=Market_MSNIS_Taglines Start enjoying all the benefits of MSN® Premium right now and get the first two months FREE*.
