2/3" CCD is only 11mm diagonally

[1]

I never knew this until today: a 2/3" image sensor is only about 11mm diagonally.

Apparently a left-over from old tube cams: "This goes back to the way image sizes of video cameras used until the late 1980s were expressed, referring to the outside diameter of the glass envelope of the video camera tube."
http://en.wikipedia.org/wiki/Image_sensor_format

There's me holding some digital calipers up to a 2/3" image sensor, and measuring "a lot less than 17mm", assuming they cheated me and stuck a 1/2" sensor (or something like that) in there!

Doh!

[cgbier]

It is known for quite a while that our esteemed 1/2.7" HVxx sensors are only 6mm (~1/4")...

This leftovers from old formats always come in handy when marketing has to fool someone...