Overview[]
The light machine is a machine invented by Dr. Hans Zarkov that turns people invisible. The invisibility wears off after a while.
Comic strip[]
Zarkov turns Flash Gordon invisible, turning him into "the Avenging Shadow" so that he can fight Queen Azura. ("The Witch Queen of Mongo")
Serial[]
In the serial, Zarkov makes Flash invisible so that he can fight Ming the Merciless. ("Chapter 111: In the Claws of the Tigron")