Biomedical Engineering Reference
In-Depth Information
(e) 100.00 − 33.33 cm
66.66 cm
(f ) The interval of Sturm is
dioptrically
centered between the image plane of
the horizontal meridian and the image plane of the vertical meridian. The
dioptric distance from the lens is
=
3.00 D
+
1.00 D
=
2.00 D
2
This means that the circle of least confusion is located 50.00 cm from the lens.
4. (a) The vertical meridian of the lens has a power of
+
6.00 D and the horizon-
tal meridian has a power of
5.00 D. Vertically diverging object rays are
focused by the stronger vertical meridian to form a horizontal line. The
line is located at
+
′
=
L
L
+
F
(100)(1.00)
−
⎡
⎥
⎤
⎥
′
=
L
+
6.00 D
40.00 cm
′
=
+
L
3.50 D
1
l
′
L
=
′
(100)(1.00)
l
=
+
3.50 D
′
′
=
+
l
28.57 cm
(b) Horizontally diverging object rays are focused by the weaker horizontal
lens meridian to form a vertical line. The line is located at
′
=
L
L
+
F
⎡
⎥
(100)(1.00)
−
⎤
⎥
′
=
L
+
5.00 D
40.00 cm
L
′
=
+
2.50 D
1
l
′
L
=
′
(100)(1.00)
l
=
+
2.50 D
′
l
′
=
+
40.00 cm
(c) 40.00 − 28.57 cm
=
11.43 cm
(d)
3.50 D
+
2.50 D
=
3.00 D
2
Therefore, the circle of least confusion is located 33.33 cm from the lens.
