10-19-2010, 02:08 PM
Variable ND filters are not that new.
Singh-Ray Vari-ND is around some time.
You can put two linear polarizer together: Voila! Vari-ND!
Or use two linear polarizer filter gels.
To test the application you can try 2 circular polarizers. Screw in the first and just hold the second one reversed in front of it. Output is crap, serious problems with "hot" spots.
Ciao, Walter
PS: Linear polarizers may cause phase detection AF and exposure measure to fail. Use live view instead.
Singh-Ray Vari-ND is around some time.
You can put two linear polarizer together: Voila! Vari-ND!
Or use two linear polarizer filter gels.
To test the application you can try 2 circular polarizers. Screw in the first and just hold the second one reversed in front of it. Output is crap, serious problems with "hot" spots.
Ciao, Walter
PS: Linear polarizers may cause phase detection AF and exposure measure to fail. Use live view instead.