This is tonight's experiment. Two TL videos merged over about 45 minutes. I let it go dark at the end. I had another segment but it was just too dark. In fact I re exposed as it started, but that made it much brighter than the end of the previous segment, but it quickly got very dark.
Canon EOS RDSR at f8, about 100 mm. 4 second intervals.
Canon EOS RDSR at f8, about 100 mm. 4 second intervals.