Originally posted by monochrome How many photographers today are actually old enough to have ever used a manual focus lens? And of those, how many actually even want to?
And how many people will spend $2,000 on a state-of-the-art autofocus and metering system complete with modern lens distortion and CA correction built-in to run a $30 Fleabay manual focus lens?
I've said it once I'll say it again, the problem for Pentax is not the FF body; it's getting people to invest (quite heavily) in new FF Pentax glass. As with APS-C the Ff mark splits into those who want a super-camera with all the pro features (and video) in a D600 size package, that can do long glass, wide glass, fast glass, WR glass, and compact prime glass all in one.
And there's the evolving market of more practical shooters like those who buy the Sony RX-1, who invest carefully in glass first, value portability and networking, shoot mostly urban and family with the occasional landscape, and who are on a budget.
It's almost impossible to get a single FF DSLR to play into both those markets, and Pentax needs all those potential purchasers to buy in to make it work. What will make it easier is if the price point for FF drops thanks to Canikon warring it out with Sony.
What is brutally brutally hard to sell against is a D700 with only 5,500 clicks on it, going for US$1,300 on Craigslist. Wait until the rock bottom D600's start to sell used next year at US$1,300 with 5,500 actuations and the kit lens. That's the market keeping Pentax awake at night wondering how many new lenses they'd need immediately at FF launch to get those customers away from the vast Canikon array both new and used.
Used Pentax legacy lenses are a barrier to future sales as are used Canikon bodies. What really makes a Pentax FF feasible is the simple fact that not everyone is enamoured of Canikon. Consumers like choice...and Sony generally sucks and is not really seen as a camera company.