Two days ago, I reviewed the SmallRig plate for the Sony a7III/a7RIII/a9 cameras. I found that the shoe that engages the tripod head clamp was wider than the Really Right Stuff (RRS) plates, making engagement with the cam-lock quick-release RRS clamps very tight. Today, I measured the dimensions of the bottom of a group of RRS and SmallRig plates. Here’s what I got:
It’s pretty clear that the SmallRig design center is greater than that of RRS.
I did not measure the angle and inner dimension of the plates, because I don’t have the tools to do that.
Some interesting reading on the Arca-Swiss “standard”: