3B Scientific Optical Bench U, 1200 mm - Manual (Page 20)

20
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When the iris is positioned at 35 cm a much im-
proved image is obtained.
•
Even transparent objects (preparations) can be de-
ployed. The magnification factor in this model is
not very large. In practice the focal lengths are much
smaller.
Experiment 19: Model of an astronomy telescope
19.1 Equipment:
•
Optical bench U17150
•
Concave lens f = +100 mm U17102
•
Concave lens f = +300 mm U17105
•
2 optical riders 75 mm U17160
19.2 Set up
•
Place lens f = +100 mm at the 0 position.
•
The lens f = +300 mm is moveable
19.3 Procedure
•
Sight a distant object (at least 10 m) using the lens
f = +100 mm.
•
Slide the lens f = +300 mm along the bench until
the object can be seen in sharp focus. The image is
inverted and bright.
Experiment 20: Model of a camera
20.1 Equipment:
•
Optical bench U17150
•
Concave lens f = +100 mm U17102
•
Iris U17010
•
Projection screen U17125
•
2 optical riders 75 mm U17160
•
1 optical rider 30 mm U17161
20.2 Set up
•
Place the lens f = +100 mm at the 30 cm position.
•
The projection screen is moveable
20.3 Procedure
•
The optical bench is lined up with an object and by
sliding the screen in the direction of the lens a sharp
image is produced. The image is upside down.
•
By placing the iris behind the lens the image be-
comes more sharply focused but also less bright.
The depth of focus is not critical here.
Experiment 21: Model of a Galileo telescope
21.1 Equipment:
•
Optical bench U17150
•
Diverging lens f = –100 mm U17106
•
Concave lens f = +300 mm U17105
•
2 optical riders 75 mm U17160
21.2 Set up
•
Place lens f = +300 mm at the 30 cm position.
•
Lens f = –100 mm remains moveable
21.3 Procedure
•
Use the lens f = –100 mm to sight a distant object
(at least 10 m).
•
Slide the lens f = +300 mm on the bench until the
object is sharply focused. The image appears up-
right and bright.
Experiment 22: Polarization, model of a polarime-
ter
22.1 Equipment:
•
Optical bench U17150
•
Experimental lamp U17140
•
Object holder, shaft-mounted U17000
•
Rotating object holder U17001
•
Prism table U17020
•
Concave lens f = +50 mm U17101
•
Concave lens f = +100 mm U17102
•
Round cells U14313
•
Polarization filter U40129
•
Projection screen U17125
•
6 optical riders 75 mm U17160
•
1 optical rider 30 mm U17161
•
Plug-in power supply unit U13900
22.2 Set up
•
Place the experimental lamp vertically on the rail
at the 0 position.
•
Set up the lens f = +50 mm at the 8.5 cm position.
•
Place the object holder at the 13.5 cm position.
•
Place the prism table at the 20 cm position.
•
Set up the rotating object holder at the 28 cm posi-
tion
•
The projection screen is positioned at 100 cm.
22.3 Procedure
•
The lamp's filament can be seen on the screen.