I want to set my 5D MKIII on some sort of spinning platform at the center of a table and achieve an even spin-pan with adjustable speed. Can anyone think of something like this, inventable or that already exists?
CamRanger sells a motorized tripod head that provides very smooth pan & tilt. They can be driven remotely from an iPad with the CamRanger Wi-fi or also include a cabled joy stick for steering it.
It's about $230.
I have one that I use for positioning a camera for still photography.
I am new to DSLR video (or any video for that matter) so am still struggling to get sharp focus on a good day. I did some experiments yesterday with rotating a Canon 70D that seemed like they were almost in focus. If I get a chance I will do the same experiment with my Canon MK2.
The motorized head has a slow mode that can run on batteries or AC current. They both rotate pretty slowly. I put a rheostat on the electric feed and was able to get it to rotate even slower. My hunch is that this is exactly what you want, As soon as I can master focus in general I will experiment again and report back.