PASCO OS-8500 INTRODUCTORY OPTICS SYSTEM - Manual (Page 71)

012-02744K Introductory Optics System
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do di m Real/Virtual Inv/Uninv
f/16 -f/15 16/15 Virtual Uninverted
f/8 -f/7 8/7 Virtual Uninverted
f/4 -f/3 4/3 Virtual Uninverted
f/2 -f 2 Virtual Uninverted
3f/4 -3f 4 Virtual Uninverted
7f/8 -7f 8 Virtual Uninverted
15f/16 -15f 16 Virtual Uninverted
f No image formed (A.K.A. “Image at Infinity”)
17f/16 17f -16 Real Inverted
9f/8 9f -8 Real Inverted
5f/4 5f -4 Real Inverted
3f/2 3f -2 Real Inverted
7f/4 7f/3 -4/3 Real Inverted
15f/8 15f/7 -8/7 Real Inverted
31f/16 31f/15 -16/15 Real Inverted
2f 2f -1 Real Inverted
33f/16 33f/17 -16/17 Real Inverted
17f/8 17f/9 -8/9 Real Inverted
9f/4 9f/5 -4/5 Real Inverted
5f/2 5f/3 -2/3 Real Inverted
11f/4 11f/7 -4/7 Real Inverted
23f/8 23f/15 -8/15 Real Inverted
3f 3f/2 -1/2 Real Inverted
5f 5f/4 -1/4 Real Inverted
10f 10f/9 -1/9 Real Inverted
100f 100f/99 -1/99 Real Inverted
Exp 19: The Projector
➃
It is not possible to project an uninverted image
with one lens. (This is why projector slides must be
put in upside down and backwards.)
➄
The image from a projector may be viewed with-
out a screen, but the observer must be looking to-
wards the lens, on the opposite side of the lens
from the object.
The observer will see the image floating in space on
the near side of the lens. (This is easiest to see when
the magnification is about one.) It will be somewhat
difficult to focus both eyes on the image at the same
time, but when it happens, the effect is startling.
➀
If the object distance is less than the focal length of
the lens, then the image formed is a virtual image,
located on the same side of the lens as the object.
This can not be focused on a viewing screen.
➁
If the object distance is greater than 2f, then the im-
age will be reduced in size. It will still be a real im-
age, so it may be focused on the screen.
➂
One practical limit to the magnification is the size
of the lens used, another is the amount of light
available. Magnified images are dimmer than re-
duced images, because the same amount of light is
spread out over more area. If the image is magni-
fied too much, it may not be visible.
Object Lens Image View from here