Originally posted by Rupert Maybe the Japanese are right?
Rupert, good point.
They are right, to a certain point.
#1 reason for a TC was to be able to compose the image on slide material (film). Last century.
#2 reason is to zoom into an image to obtain more detail. That was a valid point with a *istD. Not anymore with 90% of lenses. Last century.
#3 reason is to boost the resolution limit for the best of primes, even with a 4.7µm pitch sensor which requires lens+TC to resolve 150 lp/mm which is rather hefty. But the best lenses can do this, esp. with digital sharpening aids.
#3 is a valid reason, Tokyo should not ignore. I'm just not sure how well the countries can argue when it comes to technical detail. Them and Tokyo don't normally play in one league.
#3 is decisive at the moment where the Pentax system is restricted to 300mm and would have to grow to 500+ mm to be competitive. A 1.4x TC would help a lot.
IMHO, the TC is a no-brainer (as it is already in prototype stage) and the missing lens really is a fast focussing very sharp 500/5.6 for around $2000 (which should be the expected MSRP applying a diameter-squared price scaling formula and assuming the DA*300/4 is $1400). Screw drive plus ring motor SDM.
I really think such a lens would sell well. I got the impression that Pentax would build and sell such a lens if they can seriously expect to sell more than 500 per year. That's significantly less than 0.5% per K-5 buyer. Come on, let's do a preorder party and make Pentax committ to at least one cool tele lens.