Biomedical Engineering Reference
In-Depth Information
Calculation of f
e
and f
e
′
n
′
f
e
′
F
e
=
(1.00)(100)
+
26.93 D
=
f
e
′
f
e
′
= +
3.71 cm
This distance is measured
from
the secondary principal plane,
H
′
.
Since the lens is surrounded by air,
f
e
is equal to
−
3.71 cm. This distance is
measured
from
the primary principal plane,
H
.
Location of principal planes
:
t
⎛
⎞
⎠
F
2
⎝
A
1
H
=
F
e
⎛
⎝
0.030 m
⎞
⎠
(
+
20.80 D)
1.52
A
1
H
=
(100 cm/m)
+
26.93 D
A
1
H
= +
1.52 cm
t
⎛
⎞
⎠
F
1
−
⎝
′
A
2
H
=
F
e
0.030 m
⎛
⎝
⎞
⎠
−
(
+
10.40 D)
1.52
′
A
2
H
=
(100 cm/m)
+
26.93 D
′
A
2
H
= −
0.76 cm
Calculation of F
n
and F
v
:
We can calculate
F
n
and
F
v
using the thick lens formulae:
F
2
F
n
=
+
F
1
1
−
cF
2
+
20.80 D
F
n
=
+
10.40 D
0.030 m
1.52
⎛
⎝
⎞
⎠
1
−
(
+
20.80 D)
F
n
= +
45.69 D
F
1
F
v
=
+
F
2
1
−
cF
1
