RCA camera
Well…I presume that's a 2/3" diameter circle…and thus would
hold a rectangle with a 2/3" diagonal…or about 18mm.
How about this: take a 35mm SLR and look thru the viewfinder, now
set up a video camera beside it and zoom in or out until you have the same
field in the viewfinder (or as close as you can get depending on the aspect
ratio) and then read the focal length off the zoom? That ought to give you
and idea what a normal lens for a video camera should be. (Oh…forgot to
mention, put a 50mm lens on the SLR)