PASCO OS-8500 INTRODUCTORY OPTICS SYSTEM - Manual (Page 73)

012-02744K Introductory Optics System
®
67
Exp 22: The Compound Microscope
Suggestions on – Procedure
➀
The image is magnified; but at 150mm objective
distance, the magnification is not significantly
more than when the 75mm lens is used as a mag-
nifier.
➁
The magnification increases dramatically as the
objective lens moves closer to the object. This is
because the projected image of the object becomes
larger as the distance between object and objective
gets closer to the focal length of the lens. (The im-
age will be lost entirely when the objective is
75mm from the object.)
➂
Spherical aberration becomes quite a problem, and
chromatic aberration becomes significant at the
very high magnifications.
➃
The smaller the aperture is, the sharper the view
through the microscope. A very small aperture
eliminates both chromatic and spherical distortion,
and allows higher magnification.
➄
Small apertures make the image quite dim. (You
may want to use the lamp to illuminate the
viewscreen.)
➅
The magnification would be higher.