I read that the cold opening to the first part of "In a Mirror, Darkly" was shot on 35mm film so as to match the scenes from First Contact.
The first three seasons can be rescanned in native 4K, but the fourth season can only be upscaled from 1080p.
The first three seasons can be rescanned in native 4K, but the fourth season can only be upscaled from 1080p.