PASCO OS-8500 INTRODUCTORY OPTICS SYSTEM - Manual (Page 68)

Introductory Optics System 012-02744K
®
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➂
A slightly blurred image is still visible. (The room
must be fairly dark for this image to be visible.)
➃
The smaller the aperture, the sharper the focus.
➄
The magnification increases with distance.
➅
Chromatic Aberration
Note: This effect is difficult to see unless the
room is dark and the magnification is high.
➀
The light that travels through the edge of the lens is
bent more, thus the difference in the amount of
bend of the different colors is more visible.
➤ ➤ ➤ ➤ ➤Notes: Everything in this lab applies directly
to photography. It may be interesting to do the
experiments described here with a lens from an
SLR camera, and compare the amount of
distortion.
Object
Image
Aperture
Diverging rays
from object
Light radiates from the object in all directions, but a
small aperture selects only certain rays of that light.
The rays selected by the aperture will be approxi-
mately parallel, and form an inverted image as shown.
➀
Narrower spacing makes wider diffraction patterns
➁
The larger number of slits makes the pattern
brighter, and somewhat sharper.
➂
There will not be complete agreement due to dif-
ferences in eyesight and perception of color.
➃
Color is a very subjective measurement; different
people will see the same wavelengths as being dif-
ferent colors. In addition, different people may not
even be able to see some colors. Most people will
not see as far into the violet spectrum as this, for
example, but they will see farther into the red.
Exp 15: The Diffraction Grating
A = 1.89E—4
L = 4 4 . 9
Color X1 (cm) X2 (cm) Wavelength 1 Wavelength 2
Violet 9.5 10.7 392.3e—9 439.3e—9
Blue 10.7 12.3 439.3e—9 500.7e—9
Green 12.3 14.0 500.7e—9 564.1e—9
Yellow 14.0 14.5 564.1e—9 582.4e—9
Orange 14.5 15.0 582.4e—9 600.5e—9
Red 15.0 19.0 600.5e—9 738.6e—9