I followed the project https://github.com/thomasjacquin/allsky and https://www.instructables.com/id/Wireless-All-Sky-Camera/ to build an allsky camera for my future observatory.
Big problems with the isolation and to much fights with dew and water (rainy days, good test).
It’s an RasberryPi 3, ASI290MM and 5 Megapixel CS Mount Fisheye Lens 1/2″ 1.55mm Wide Angle with 185 degree.
Finally some nichrome wire (1m 0.24dia) for heat the dome surface connected to an automatic and small thermostat solved the problem with dew.