From Time Machine
This 55-megapixel timelapse consists of over 15,000 frames and was shot from Mount Washington. Four Canon T2i's running off a car battery were used on a custom tripod mount, with each frame being taken about every 4 seconds.
The shoot occurred on December 8th, 2011 from 6 am to midnight.
This was also the same day that there was a Steelers football game at Heinz Field. If you zoom in at around 8pm, you'll see the.
Here are a few additional interesting highlights captured by this timelapse.