The PolarPro Filter Calculator is a convenient tool that helps cinematographers to quickly find the correct filter to get shutter speed as close to double the frame rate as possible. Simply plug in your native shutter speed, and FPS into the calculator to determine what filter is best suited for your current light conditions. For ease of use, the calculator lets you plug in these variables with or without a filter already installed, so that you can select the filter that gets you as close to the 180 degree rule of shutter without any of the headache. The Filter Calculator is designed for use with drones but can be also be used with any other camera and filter combination, to capture the smoothest cinematic quality video possible.