CAME-TV has a new Camera Rig Package for the Sony a7S III. It is being billed as a complete rigging solution for your camera.
Systems like this are not going to be for everyone, but if you prefer to use a matte box and a follow focus instead of variable ND filters and autofocus, this might be a good solution.
The package consists of a camera cage, top handle, riser plate with 15mm rod holes, 2x 20cm 15mm rods, a 15mm rod mounted follow focus, a matte box with a carbon fiber flag, and various sized lens clamping rings.
This package not only fits the a7S III, but it will also work with the a7SII, a7RIV, a7RIII, a7RII, a7MIII, a7MII, a9MII, and a9. It doesn’t work with the a7, a7S, or a7R.
Price & Availability
The CAME-TV Sony Camera Rig 15mm Follow Focus Rod System and Matte Box With Carbon Fiber Flag Package retails for $488 USD which makes it pretty affordable given what you get.