Originally posted by dafbp About the 70-200: does f4 vs f2.8 means mandatory (as in laws of physics) worse IQ, or is that just a design decision (as in f2.8 is for pros, so f4 doesn't need to be good just cheap)?
Can't a "slow" lens have "pro" IQ, while being smaller, and (hopefully) cheaper?
Yes (although it won't be necessarily much cheaper). When Canon introduced their first 70-200 f4 back in the late nineties, some thought it was even better than Canon's 70-200 f2.8 of the time.
Pentax currently has a number of very good "slow" aperture lenses in their lineup: 15/4, 21/3.2, 16-85/3.5-5.6, 12-24/4, 17-70/4, 28-105/3.5-5.6. Even the new 55-300/4.5-6.3 is very good in the 55 to 135 range.
---------- Post added 02-28-18 at 06:23 AM ----------
Originally posted by kenspo My job is to attract new pro users to the Pentax system. Hard enough as it is already. Wont be any easier when I have to say "Sorry, we dont have a 85 1.4, but we can offer a 70-200 F/4"....you can guess the result..
Since both lenses are scheduled to be released in 2019, there won't exactly be a very long gap between the release of the 70-200/4 and the 85/1.4.
---------- Post added 02-28-18 at 06:26 AM ----------
Originally posted by dafbp Everybody talks about slow vs fast lenses as low IQ/cheap lenses vs pro, but I'd really rather have a smaller/slower lens, but with the same IQ, than a big fast lens.
So would I. Back in September of 2017, I seriously considered getting a K-1. But the weight of the DFA 15-30, which weighs as much as my DA* 300, was simply a bridge too far, so I bought a KP instead.