Today I want to take a moment and give a quick shout out to one of my favorite camera mods that is tucked away in a hidden corner of the internet: the ClearSight USA Hasselblad to Arca Foot Adapter.
Some of you may not be aware that your 500 series Hasselblad camera actually has a built-in quick release on the bottom. The problem is that its specific to Hasselblad, and few people still use the quick releases made for that plate. What most people wind up doing is putting a removable plate on top of the Hasselblad QR plate, which winds up being both uncomfortable in the hands and adding bulk to the camera.
After scouring the internet, I found this company manufacturing a replacement for the stock plate. Its not really any more bulky than the stock plate, its smooth and comfortable to hold, and it works perfectly with my RRS BH40. Its an elegant, comfortable solution to a minor but annoying problem. For whatever reason I never see anyone write about this product and its hidden on the website of a company that makes lens cleaning fluid, so folks are unlikely to find it. I haven't seen any of the other big plate manufacturers offer a stock replacement plate, as opposed to one that fits over the original.
The product itself is nicely made with comfortable smooth edges and good finish. The one pictured has been used for a year or two with no significant blemishes. All in all I recommend you consider this product if you're using a Hasselblad and use Arca-compatible tripod mounts such as the ones on Really Right Stuff, Markins, or Kirk ballheads.