In article , Commander Kinsey
wrote:

https://www.dropbox.com/s/ctqungbvve...field.jpg?dl=0
This is a snapshot of Startrek The Next Generation, Season 6, Episode 26.
It appears to have two planes of focus, one centred on the right eye of the
man in the foreground, and one on the right side of the chest of the man in
the background. Two cameras with superimposing? Or some effect put in
afterwards?

it's not two planes of focus.