Pentax lenses on the BMDPC,... yuuuup, shot this on it -
I Miss The War (2018) - IMDb
Also had my K/KM/KA lenses in front of the original BMD 2.5K camera on M4/3 and EF, and in front of the BMD Production Camera 4K with EF mount, as well as my AJA Cion with the same sensor as the original BMD's and Ursa's use for 4K.
It's very much a case of the Lenses being superior to the Camera
On the Pocket, make sure you use a cage to protect the DC input - the factory power pack is stupidly fragile.
Those BMD's all have a little error in the mounts, as they were made to accept a wide range of lenses of varied machining quality, so be prepared to adjust the shimming of your PK-to-M4/3 adapter, to get the correct Flange Focal Distance. Once done, the focus at wide open, especially at infinity, will be much more accurate, and very crisp.
Forget relying on the internal battery - even if the camera is switched off, you'll only get 20 to 25 minutes battery life, so a DC adapter with an NP-F cradle on the top of your camera cage is a must.
So is using external Audio Recorder - I use the Tascam DR-70D, which is slim enough to fit under the BMDPC and can feed Mic or Line level out to the BMD's Stereo Jack Input.
One issue that's popped up in the last year, is changes to the SD-XC cards by the card manufacturers - there were very few SD-XC cards that could write the speeds needed for Internal Raw, and some of the changes made since mean that versions that should work in the BMDPC, don't any more. There's more info on this over on the Blackmagic Design user forum.
The other issue with the BMDPC, is that it's Rolling Shutter Skew (how much vertical objects warp as you pan past them) is pretty woeful. To the point we decided to not shoot handheld at all for the short film I linked above. I mounted the BMDPC on the hotshoe of my K-01, so they were on the same tripod, with a 50mm on the K-01 and 24mm on the BMD to give nearly identical Field of View, then panned side to side. At the speed of moving side to side that made the BMD footage unusable, the skew was barely noticeable on the K-01.
Hand Held on the BMDPC
ABSOLUTELY REQUIRES the use of a Gimbal.
Also, Protect Your Highlights. The BMDPC blows out highlights real fast, even faster then the AJA Cion, and once they're gone, there's no post recovery that can help.
It's very much a camera of Expose To Highlights and then get the Gaffer to add ambient fill to get the scene where you desire.
Once all that is done, the imagery is beautiful, retaining detail and subtlety that many cameras can't come close too. The Colour Science and Skin Tones aren't anywhere close to what the K-01, K-3, K-1 can do, and all of them have better dynamic range, but the advantage of the BMDPC is much more detail due to the much higher data rate and lower compression.