Dave C writes:
Which brand of 9 stop ND filter do you use with Noctilux? I'm think of buying a good quality ND filter to use shooting landscapes wide open with my Zeiss.
DIGLLOYD: To get 9 stops, I use a 3 and 6 stop ND filter, stacked. I do it that way because use of 3 or 6 stops alone are more frequent usage for me. Also, the greater densities filters are often not multicoated, and the 3, 6 stop filters are multicoated.
The ND filter numbers are not intuitive unless you’re a math person:
- ND 0.3 = 1 stop
- ND 0.6 = 2 stops
- ND 0.9 = 3 stops
- ND 1.8 = 6 stops
- ND 3.0 = 10 stops
On a Nikon DSLR with 1/8000, you can get away with 2 stops of density for allowing f/1.4 in bright sunlight conditions. With a Leica M9, the top 1/4000 speed mandates 3 stops for the brightest conditions, and that’s at ISO 80.
For blur effects, go with 6 stops or more, but there can be very limited choices depending on filter size and whether or not multi coating is available. Another option is a dual polarizer (“variable ND”), but the review sample I have on order has not yet arrived, so I can’t speak to that directly so far.
As ND filters get darker, color balance tends to get warmer and warmer, which must be noted when setting white balance.
One can combine minimal depth of field with motion blur, or stop down for image sharpness for static elements, allowing motion blur to blur away moving items. Experiment with various shutter speeds and apertures; a fast lens yields the most possibilities for combining the two effects, so choose an f/1.4 lens or faster.