Originally posted by swanlefitte One of the main things I want in a camera for video is to operate it without any twist in my wrist or forearm. Holding for extended time is fatiguing, moving to follow a scene is harder to flow, and fingers become less dexterous with arm/wrist swirl. My ks-2 is terrible for this, my k100d is much better until you need to do anything but press the shutter and even the asahi pentax s is better.
That wrist loading has been a factor since the days of VHS-c, Hi-8 and DV - all the 'consumer' camcorders went smaller, single handed, and that let to operators who moved from them to larger sensor cameras, and still using them one handed.
Oddly enough, in the manuals for the Pentax film era SLR's, there used to be a set of guide images on how to hold the SLR for most stable images, right hand on the grip, left hand under the lens, film cover to the cheek, elbows in to the body.
This grip works for taking stills, and is also the ideal grip for doing video, far more stable then single handed with hands and elbows away from the body to look at the LCD, and is still possible with Mirrorless with EVF, and DSLR's with hybrid EVF/OVF viewfinders.
Even on a body as large as the 645Z, this grip gives a stable platform to the camera and smoother motion.
Using that grip on the K-3iii, perhaps with a Loupe over the LCD, and with the mechanical stabilization being back on, should give exceptional results, far beyond any single handed camcorder can achieve.
For hand-held filming, the only other way to alleviate the sort of arm, shoulder, and spine aggravation that the Two-hands-out-front method leads to, is a an ENG / Cine Rig, putting the camera body up in front of the shoulder, with external viewfinder.