Switching the public lighting off

The next two frames are made consequentially around the time that the street lighting is switched off (midnight during the week). Normally the SQM drops then about 0,5 points. It also shows up in these frames as it instantly becomes darker. The frames are completely identical. No Light Pollution filter was used.  There was some light fog in the air but not too much, SQM value around 20,15 before and 20,40 after. Image of Wirtanen, tracked on the comet for 2 minutes. 

Comet Wirtanen December 7th

Wirtanen, stacked on the stars and the comet using PixInsight by Jean Lammertyn. Nikon D750, Nikkor 180mm ED 24x120s ISO400
Comet Wirtanen 46/p with Nikon D750 Nikkor 180mm ED ; no filters ; 12x30s on ISO800 ; processed with APP and Photoshop – no guiding & stacked on the stars ; crop from the original frame ; the shadows to the left in the image are tree branches that traced in the first few frames;
Equipment: Nikon D750, Nikkor 180mm ED F5.6 ; 24x120s on ISO400 ; processed with APP and PS ; stacked on the stars

Wirtanen Video

Comet Wirtanen clearing a large tree in my garden. Actually an MP4 of the NEF Nikon frames used to create the pictures above.