12 Sep
2011
12 Sep
'11
12:40 p.m.
On 9/12/11, erikhansen@thebluezone.net <erikhansen@thebluezone.net> wrote:
Orion cells a set that rotate to give 50% to 0% transmission. I use them on the moon.
That's the type you want, and they are for density only. Many DSLR camera "polarizing filters" are not for variable density, just glare reduction in outdoor photos. Those won't work in this application as they are a single filter, not a double.