Quote: Pentaxor:there are just too many great 35mm lens options that it won't make sense putting or buying an MF (medium format) lens to a Pentax APS-C dslr. although surely there are great MF lenses out there, but some of those great MF lenses are rare or can be expensive. thus buying a 35mm lens would be much more logical choice. an MF adapter would be hard to find and pricey as well. an M42 adapter for a lot of M42 35mm lenses is cheap and easy to find. and there are lots of nice and cheap Taks and other 3rd party 35mm lenses available.
lastly, it would be pointless to use an MF on any APS-C dslr due to crop factor. the main idea of having an MF lens is for a wider perspective, DOF and far better resolution due to lens and camera capability, which you can't do on an existing APS-C camera. if you really want to make the best out of an MF lens and fully utilize it, buy an MF body. you don't buy a lens that you can only use 50% or less of it's capability.
I disagree, it can make a lot of sense--did you read my first post???. Please re-read my first post in this thread! Comparing my MF 330mm to my K300 f 4, I'll summarize why once again--very briefly.
Focal length= +1 to Medium Format lens 330mm over K 300mm f4
TRi-pod mount= +1 to 330mm Medium Format lens over K 300 f4
Iq & Sharpness= +1 to 330mm Medium Format lens over K 300 f 4
Close Focus= +1 to 330mm Medium Format over K 300 f4
Cost=+1 to MF over over K300 f4
Weight= +1 to MF 330 over K 300 f4
Speed= + 1 to K300 f4--which isn't very impressive wide open anyway
I'll take the Medium Format, $100 lens over the K300 f4 any day of the week.
Finally, it is amazing how much better CA control is with the Medium Format setup when compared with the K 300 f4--like night and day.