PASCO OS-8500 INTRODUCTORY OPTICS SYSTEM - Manual (Page 47)

012-02744K Introductory Optics System
®
41
EQUIPMENT NEEDED:
-none
Experiment 18: Introduction to Optical Instruments
Introduction
The design of high quality optical instruments can be quite complex, involving compound lenses
and intricate lens coatings. But the complexity arises primarily from the need to reduce the
effects of spherical and chromatic aberration (see Experiment 14). Understanding the basic
principles of standard optical instruments is not complex. It requires only an understanding of
the Fundamental Lens Equation:
1/d
o
+ 1/d
i
= 1/f;
for which the magnification of the image is given by the equation:
m = -d
i
/d
o
.
In Experiments 19-22, you will use the above equations to investigate the workings of a Projec-
tor, a Magnifier, a Telescope, and a Compound Microscope. Before beginning, however, it is
useful to understand certain generalities that can be made with regard to these equations.
Procedure
Use the Fundamental Lens Equation to complete Table 18.1, on the following page. Show the
location (d
i
) and magnification (m) of the image, and whether the image is real or virtual, in-
verted or uninverted. Notice that d
o
is given in units of f. Your calculated value for d
i
will
therefore also be in units of f.
After completing the table, use it to answer the following questions. In each question, assume
that f > 0 (as for a converging lens). A negative value for d
i
indicates that the image is virtual.
➀ For what range of d
o
values is the image virtual and magnified?
(Remember: d
i
= )
➁ For what range of d
o
values is the image real and magnified?
➂ For what range of d
o
values is the image real and reduced in size?
➃ For what range of d
o
values can the image be focused onto a viewing screen?
d
o
f
d
o
- f