>> " . . . it is somewhat disturbing to buy a modern camera and find that something as fundamental as the focus screen calibration is sloppily applied by the factory."
Pentax COULD design and produce bodies such that each incremental manufacturing tolerance was miniscule and each unit had a custom, hand-fitted VF shim to accommodate residual assembly variations -- and they COULD replace all tooling weekly to maintain perfect tolerances and QA goals -- and they COULD conduct 100% QA sampling -- and those of us with a Rolls Royce with driver and a gold Rolex or three could maybe afford 'em.
A more practical plan is to accept nominal, economical manufacturing and assembly tolerances and adopt a statistical QA sampling process using a medium shim that would allow adjustment in either direction if after-sales dissatisfaction deemed it necessary.
We can't have an affordable body that can use millions of lenses (including those built decades before the digital era!) and still expect perfection in every detail of practical use. Personally, I believe shims and software accommodation for AF adjustments is a practical solution and I'm very willing to accept that slight inconvenience in return for a
highly versatile,
affordable,
modern digital SLR body regardless of the Brand Name on the front. And that includes the possibility of having to return, repair or adjust a body on rare occasions too -- incidentally, I've never personally had to do that in nearly half a century of using Pentax photo gear.
Face it, guys,
mass produced, affordable photography gear isn't going to be designed and manufactured to space program or brain surgery tolerances. I'd invite everyone to conduct their personal business to the same degree of perfection and accountability they'd like to hold Pentax to.
It's not that the pig whistles so well, but that it whistles at all that should amaze us.