OD---optical density
OD=-log(T)
		

OD	Transmission	
OD1	=0.1 or 10%		
OD2	=0.01 or 1%		
OD3	=0.001 or 0.1%		
OD4	=0.0001 or 0.01%		
OD5	=0.00001 or  0.001%		
OD6	=0.000001 or 0.0001%
		
BlockingCode 	BlockingRange		
A	         400-1100nm		
B		 300-1200nm		
C		 200-2000nm		
D		 400-700nm
E		 400-800nm
F		 400-1000nm
G		 300-900nm
H		 500-1000nm
I		 800-1000nm
J		 700-1200nm
K		 200-1100nm
M 		 200-1400nm
N       	 	400-1200nm
O       	 	200-1150nm
P       	 	200-800nm
Q       	 	350-700nm
U        	 	200-700nm
V       	 	300-950nm
W       	 	200-1000nm