Originally posted by thePiRaTE!! I personally burst at the seams at the idea. I'll be able to use my 125 as I use my 85 currently, my 85 as I use the Nokton (58) and the Nokton will become a more interesting normal. I'll capture all the swirly goodness the Biotar offers and capture the strong edges my money bought with the 25mm (without it 'becoming' a 37.5) Distagon.
Due to being able to stand closer to my subjects, given the extra image captured, I'll be able to work in a shallower depth of field if I choose and thus increase - bokeh. Its a magic word to me. One small change to a sensor makes a lot of interesting changes to everything I shoot.
On the other hand, the K20 is the only DSLR that offers the selection of manual lenses, at the price it does, with the SR in the body and live view to take full advantage. Very sweet.
Sony A900 has the SR, the MP, and a top notch view finder (so I've read), but no chance of any of the newer manual Zeiss and Voigts to take advantage of the inbody SR (and no live view). Existing AF Zeiss are paid for at a serious premium for a feature that actually detracts from how I'd use it.
Canon 5D mkII has almost equal MP to A900, decent noise performance and yes... movie mode if you care about that. For me that means perhaps missing shots while shooting movies, leading to a new harddrive array and more software. Good lens selection in the manual primes catagory though.
Nikon has the D700 which has the best selection of glass in my field of interest next to Pentax, best ISO - which goes some ways to making up for no inbody SR, but at a penalty. IQ directly compared to K20 wants to be tested. It would be nice to have smaller files for a change though. Currently my secret fantasy.
Ideally, I'd love a K20 with a full sensor. Change nothing except the sensor and I'd pay the full price of admission to the full frame catagory, 3k.
You have some very specific lens choices which really dont apply to many people. I get as much "bokeh" from an APS camera because I can access faster tele lenses for the same money.
A 50 F1.4 is a lot cheaper than an 85 F1.4 last I checked, and has almost the same DOF as a 77 F1.8 would on an FF camera....for much less money.
The 50-135 F2.8 on a K20D provides the same DOF options as a Canon 70-200mm F4 on a 5Dmk2, which is about the same price (in IS mode). The Nikon 70-200 F2.8 gives a stop more DOF but is vastly bigger and more expensive (as is the Canon version). The Sigma 70-200 F2.8 is also much heavier and more expensive than the Pentax.
My FA* 200 F2.8 has the same DOF as a DA* 300 F4 would on an FF camera.
Again, same size and weight. So yes you can get shallower DOF on a FF camera, but only by buying faster long glass which is more expensive and heavier than the APS equivalent.
OK, for wide angle lenses, then its harder to find fast glass. However I use wideangle more for landscape work. In this case, I usually work stopped down and the greater DOF of APS allows me to use apertures which are slightly wider and faster (closer to MTF max) than what I would need on FF. This means sharper, especially in combination with SR.
So sorry but I dont buy this DOF argument at all.