Originally posted by Fogel70 As my trusty old K7 can record b&w video, I would expect any video capable Pentax DSLR can.
Pentax has in parts downgraded the video functionality of their cameras after the K-5, ... but yes it should be able to do it via the picture styles. Whatever you set for stills will be applied to video too.
Nope. No AF. AF on most DSLRs (only exception is the 70D AFAIK... and perhaps other cameras with that sensor) is awful anyway, DSLTs are ok and the latest mirrorless cameras. But DSLRs...
If you don't mind/are able to add sharpness while editing, try lowering the sharpness in camera as much as possible. Helps the camera focus on encoding only the actual video data... the bitrate is already too low, so wasting bits on the artificial sharpness lowers quality.
Also turn of SR in the K-3 (in K-5 turn on).