Focal Length Calculator——焦距计算器
ΦOS Power of Surface 1
ΦIS Power of Surface 2
F Lens Power
nOS Object Space Index
nL Lens Index
nIS Image Space Index
R1 Radius of Surface 1
R2 Radius of Surface 2
CT Center Thickness
P Primary Principle Point
P" Secondary Principle Point
EFL Effective Focal Length
BFL Back Focal Length
FFL Front Focal Length
NPS Nodal Point Shift
fF Front Focal Point
fR Rear Focal Point
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