Exposure Guide using Filters
For photographers, here is a free download you can use to help set your shutter speed when using ND filters.
My personal favorite filter to use is my B+W 110 ND filter which is a 10 stop filter. I created this cheat sheet to keep in my camera bag when I'm out in the field & sometimes am just too tired from driving to use my brains.. :) I know there are apps for this, but when I'm hiking in the middle of nowhere my apps on my phone don't work and the phone becomes pretty much useless.