Quick query over ND filters...

[D_Fivehundred]

Could someone just clarify the numbering system? I have an ND2 and ND4 (full and grad versions, but I've also seen

1 stop, 2 stop, 10 stop, etc
0.3, 0.6, 0.9, etc
ND2, ND4, ND8, etc

So, how do they all compare...?

 

[Apache_sim]

I came accross this recently and it was explained to me as:
ND2 =0.3 = 1 stop
ND4 =0.6 = 2 stops
ND8 = 0.9 = 3 stops

Hope that helps

 

[D_Fivehundred]

Smashing, thanks