Originally posted by les3547 It's not so much about IQ differences for me, though I still think the ultimate prime can be (but not necessarily is) better than the ultimate zoom. But if the 135mm on FF is someone's favorite walk around perspective (like me), then I'd have to lug around 1755g on my camera to use the DFA 70-200. I don't own that lens but I loved the DA 60-250's IQ. Hated carrying it.
Must photography be just for people who want zooms and massive primes? I don't think I'm alone in preferring primes that help me keep my kit as small and as lightweight as I possibly can. Pentax in the past has offered that option, which is one reason I chose them when got back into photography. I suppose I'm trying to cast a vote for Pentax not abandoning the Limited philosophy for FF.
My philosophy has always been cover everything with slow zooms. Then have a series of fast primes to cover your most used focal lengths. Some primes should be available for people, but obviously, Pentax being a much smaller player, the numbers probably don't add up for a production run.
They are clearly starting with the one's most likely to be popular, the 50 and 85. But who knows, maybe a 35 and 135 are coming. The difference to me between the 85 and 135, is the 85 can be an indoor/outdoor lens on both APS-c and FF, 135 is definitely not indoor on APS-c and barely on FF. I can't see a lens like this being introduced that is so well covered on APS-c (18-135, 50-135, 60-250, some of the absolute best Pentax lenses.). My guess is APS-c still pays a lot of the bills for the development of any lens.