Rangefinders such as this one used by John Glenn on his Mercury Friendship 7 mission in 1962, help a photographer determine the distance between the camera and the target to be photographed. The device allowed Glenn to properly focus his cameras to capture images of Earth and space, the first taken by an American astronaut. Glenn could use this device with his visor down, allowing him to put the rubber eyepiece against the visor and look through it and out the small window of his capsule.
NASA transferred this rangefinder to the Museum along with all other "Friendship 7" equipment in 1967.
