'focal ratio' definitions:
Definition of '
focal ratio
'
From:
WordNet
noun
The ratio of the focal length to the diameter of a (camera) lens system [syn: focal ratio,
f number
,
stop number
,
speed
]
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
