At a local brand new mega-multi-many-screen-a-plex theater were were watching the pre-movie entertainment (they use a DLP I believe) to show local advertising clips and movie quizes. The aspect ratio of the screen was probably 1:85. Suddenly we saw the 'power off' display from the DLP and the screen went dark.
The next thing we saw was the black masking on the top and bottom move to convert this huge stadium seating screen to a 2:35. Then the movie started.
It's all about your perspective.