Originally posted by RobA_Oz IIRC, the main difference with the 18-250 variants was the addition of SMC to the Pentax edition.
It may have been that Pentax also demanded a tighter tolerancing on manufacturing, allowing for less variation between copies. This, of course, is what happens in a number of manufacturing situations, where a higher price is put on product that falls within tighter quality specifications.
LOL,
if that was the case, we'd have the "perfect system". From your statement above, you imply that Pentax has some form of quality control a step above Tamron's. Maybe two decades ago.., but Pentax's own SDM is so bad, they have to re-brand another technology as their own (tongue in cheek). Even then they are still unable to offer an equivalent warranty (6 years versus 1 year) . If their marketing department can spin the specs of their new flagship camera, I'll take a stab at their lenses. Shenanigans, as someone mentioned before, albeit for the "new" focusing system on the K-5II ..
Once you start to dissect or dissociate the lens lineup from the bodies, you start seeing a gradual decrease in effort to maintain complementary quality between the two. It has been like that for at least a decade.
How can Tamron maintain a 6 year warranty period versus Pentax's 1 year period for their purported "quality SDM" lenses. Then factor in the recent price increase, just so they can offer a 50% discount to arrive at previous MSRP's.
Ricoh, you have your work cut out for yourself. Let's just see how deep of a hole you want to dig, before you decide it's time to get your house in order. It makes me wonder just what you bought the K-mount for!