The destinctive wedge shapes went up and down to indicate when the lift was on it's way to the top or bottom.

Taken 29th January 2016 at Holborn, London, Greater London with Canon EOS 7D

• Exposure 0.006 sec (1/160)
• Aperture f/2.8
• ISO Speed 800
• Focal Length 53 mm
• Lens EF-S17-55mm f/2.8 IS USM