There are almost no manufacturers making custom quick release plates for Pentax Camera bodies. Any that were being made by Really Right Stuff and Kirk Enterprises have pretty much been discontinued and they seem to be focusing on Sony, Nikon & Canon.
I recently found a custom plate for the Pentax K3 Mk.III made by Hejnar Photo Design who also make some plates for other Pentax models and reported this in a post "Custom QR Plate for K3 Mk.III".
But I also found a custom "L" plate make by Fittestphoto that was designed for the Pentax K5 that fits the K3 Mk.III so precicely that you might think it was designed for it. It fits against the bottom of the screen with a raised lip as an anti-twist stop. The vertical QR arm has a cut out portion that leaves just exactly enough room to access the twin rubber doors to the USB/HDMI connections and the Microphone/headset panel.
This bracket also fits the K3 and K3 Mk.II, but the same connector panels are covered by a single rubber door and it is opened from the side. You are able to access the door, but it is difficult to pull the single door to the side. not impossible, but it is hard to hook the side of the door, unlike the K3 Mk.III where the opening is in the middle and much easier to pull up.
This bracket was sold through Amazon and Ali Express, but no longer available from Amazon. AliExpress currently have it marked down 30%, I paid $44.86 CAD ($36.00 US) plus inexpensive shipping. Finnish and quality is excellent, although maybe not as "streamlined" as it could be.
They show 70 in stock, but when these are gone it will probably be discontinued. If you think you might want one I would buy it now.
FITTEST Soporte de cámara FK5L personalizado, placa L, placa vertical, agarre, Compatible con Pentax K5 Arca Swiss SUNWAYFOTO RRS|l plate|sunwayfoto platecustom made - AliExpress
Murray
Last edited by oneill; 08-08-2021 at 10:32 AM.
Reason: add pictures