It is constructed using two 138mm circular polarizers. One of the polarizers rotates and the other is fixed. It provides ND values between ND 0.6 (2 Stops) and ND 2.4 (8 Stops).
Our VNDs are constructed using two 138mm circular polarizers. One of the polarizers rotates and the other is fixed. The circular polarizers are oriented with their quarter wave retarders facing out, effectively de-polarizing on both sides which prevents accidental polarization effects in the scene and allows the Variable ND to be inserted in either orientation.
The Lindsey Optics Brilliant-Pol Polarizing Filters used in our Variable Neutral Density filters are constructed using Schott B270 "water white" optical glass and have a broadband multi-layer anti-reflection coating which dramatically reduces flare, stray light and ghost images caused by filter to filter reflection. Contrast and color saturation are increased. They are ground and polished to be very flat and will not cause distortions or focus shifts, even with long focal length lenses.
