Originally posted by house That lens was already 71 mm dia. There's plenty proof you can fit in lens motors with that sort of girth. The Fuji ones are about 1cm slimmer at their widest and they are only wide at the aperture ring.
If you go way back, even to the 1980s, some of the Canon EF lenses weren’t a lot larger than the Nikon or Pentax screwdriven contemporaries.
And I think the biggest factor in the slowing of the Pentax lens development timeline is the shrinking market. Ricoh seems to be trying to balance development and production against a shrinking market space while Canon, Nikon, Fuji, and Sony have been fighting hard over market share to keep their production levels high. It makes sense considering their relative scales. We’ll see in a few years who’s right...
-Eric