Originally Posted by
asnow
I suspect that you got an ND10 filter not a 10 stop filter. See chart.... The ND10 would be between 3 and 4 stops. A 10 stop filter would be ND1024. Sorry guys it's hard to format a chart. It keeps wanting to remove the spaces. To help read this;
For example an ND8 is Optical density 0.9, F-Stop Reduction 3 stops, % Transmission 12.5 %
Optical Density F-Stop Reduction % of Transmission
No Filter 0.0 0 100%
ND2 0.3 1 50%
ND4 0.6 2 25%
ND8 0.9 3 12.5%
ND16 1.2 4 6.25%
ND32 1.5 5 3.13%
ND64 1.8 6 1.56%
ND128 2.1 7 0.78%
ND256 2.4 8 0.39%
ND400 2.6 8.64 0.25%
ND512 2.7 9 0.20%
ND1024 3.0 10 0.10%
ND2048 3.3 11 0.05%
ND4096 3.6 12 0.02%
ND8192 3.9 13 0.01%
ND100000 5.0 16.6 0.001%