The info about the DRM at the start of this linked thread is two years old. Is this still relevant?

I don't know what PDCU is, perhaps others also don't? I never open the software CDs supplied with digital cameras. I switched from Adobe RAW developers to Silkypix a few years ago because the quality at that time was so much better that Adobe's offerings. I now use Silkypix Pro with Pentax and Sony cameras. Bibble is also said to be very good and there are several others.

I thought a version of Silkypix was delivered with the K5. If this is the case you could search the web for "Silkypix Tutorials".

I use my 17 mm fish eye on a full frame Kodak SLR/c with a Canon EOS mount and an M42 adaptor. It works well, but I agree it is little use on a Pentax digital camera. It is about the only thing I use full frame for.
Tony