with proportionally spaced (geometric progression) lines - range from 20/200 to 20/10 (6/60 to 6/3) equivalent - chart measures 24.5" x 25.5" (62x65cm) - 10 feet, 3 meter testing distance [Full description below...]
Description
with proportionally spaced (geometric progression) lines - range from 20/200 to 20/10 (6/60 to 6/3) equivalent - chart measures 24.5" x 25.5" (62x65cm) - 10 feet, 3 meter testing distance