here's a few tid-bits on his lights
and how karsh worked
http://www.sciencetech.technomuses.ca/english/collection/karsh4.cfm
i worked for a lady - trained in the 1920s+30s who was a master.
she was known by many as "karsh of providence", and like karsh photographed
heads of state and business leaders.
she used to use hot lights with barn doors, ( key, fill, hair, and background ) and later
when bulbs were scarce, she used good olde photogenic strobes with barn doors.
she still used a key, fill, hair (on a boom) and background lights.
it wasn't too fancy, she like karsh, knew what she was doing, and
made beautiful portraits.
besides lighting, she also used a sharp lens (stopped down), large format ( 5x7 ) film
and retouched with leads on the flm
( and sometimes abraded the print adding graphite dust to hot spots ).
she was quite an artist.
john