Optics > Geometric Optics > Lenses DCS#  6A65.4x

SPHERICAL ABERRATION - LENS WITH VARIABLE DIAPHRAGM

 


APPARATUS
object light source
113-01-C1
plano-convex lens with V-shaped slot
101-17-B
ground glass screen
113-01-A
optical bench
113-01-D
camera
202-09-D

DESCRIPTION
The mask has a V-shaped slot behind a vertical slot that together provide two apertures at equal distances above and below the central axis.  The V-shaped slot moves laterally so that the aperture-axis distance is continuously variable.  With the apertures near the central axis and the plane side of the lens facing the source, focus the image of the light source on the ground glass screen.  As you increase of the aperture distance, it is necessary to move the screen further away to locate the point where the two rays converge.
REFERENCE

A Continuously Variable Diaphragm for Spherical Aberration Studies, W.P. Gilbert