Originally posted by Aristophanes As sensor size goes up, lens size goes up.
For the sake of your arguments clarity, let me say that this is technically false.
Two lenses made for different sized image circles but of given equivalent specification (read: rendering the same images and image quality) have equal mechanical spec (size and weight) and its price of production monotonically
decreases (rather than increases) with sensor size. Please refrain from argueing about this established fact (should you sense an urge to do so).
Of course, full frame lenses tend to be larger than their equivalent counterparts from the APSC domain, i.e., they tend to be non-equivalent or more specifically, better than equivalent.
Btw, this is where I see an important niche still to occupy for Pentax in a full frame world: Provide "APSC-style" lenses for full frame, small
and covering the FF image circle.