Biomedical Engineering Reference
In-Depth Information
n
L
′
l
=
′
100
l
′
=
= +
34.97 cm
+
2.86 D
The image is real and 34.97 cm to the right of the objective. Its magnification
and size are
l
l
M
=
+
34.97 cm
M
=
= −
2.5
×
−
14.00 cm
(
−
2.5)(1.5 cm)
= −
6.00 cm
When viewing from the objective side, the objective lens is both smaller and
farther away than the image of the eyepiece. Therefore, it subtends a smaller angle
and is the entrance pupil.
To determine the exit pupil, we view the telescope from the eyepiece side. As
we can see in Figure A-2B, the exit pupil is either the eyepiece or the image of the
objective as seen through the eyepiece. The location of this image is
′
=
L
L
+
F
100
⎛
⎝
⎞
⎠
′
=
L
+
25.00 D
= +
17.86 D
−
14.00 cm
n
L
′
l
=
′
100
′
=
l
= +
5.6 cm
+
17.86 D
The image is real and 5.6 cm to the right of the eyepiece. Its magnification and
size are
l
l
M
=
+
5.6 cm
M
=
= −
0.4
×
−
14.00 cm
(
−
0.4)(1.5 cm)
= −
6.00 cm
From an arbitrary distance of 1.00 m, the angles subtended by the eyepiece and
image of the objective are, respectively,
1.5 cm
100 cm
tan
θ
=
θ
=
0.9 degrees
