Optical Bench Legend


All distances and diameters are in millimeters (mm) and all angles in degrees.
All distances, except as noted, are relative to the first lens vertex.
Specified is as is specified in the optical prescription.
Specified f# will include any adjustment for the Aperture Stopdown slider.
Measured is as determined by the Optical Bench.
Measured P' and H' are relative to the last lens vertex.

Positions are on the optical axis.

symbol

description

O

object plane

OD

object diameter

F

front focal point

H

front principal point

P

entrance pupil

PD

entrance pupil diameter

A

aperture stop

AD

aperture stop diameter

P'D

exit pupil diameter

P'

exit pupil

H'

rear principal point

F'

rear focal point

ID

image circle diameter

I

image plane