One of my tests from last night. This is 55 stacked 10 second exposures at ISO 3200 on the Sony A7s and the Irix 15mm f/2.4. (Stacked in Affinity Photo). The SkyGuider has the camera locked on the stars and you can see the trees and transmission lines in the foreground flying by. That's the rotation of the earth in the roughly 10 minutes I spent taking 55 exposures.
Here's setup. The Optron SkyGuider Pro with the Sony A7s + Irix 15mm f/2.4. I was just doing some widefield star tracking tests last night--ended up going into the early morning hours. The Milky Way didn't hit 30° in the east until 11pm.