The combination of two polarizing filters reduces blue and green wave length to suppress blue cast underwater.
Turning the front polarizing filter provides wide and seamless adjustment from least to maximum effect where almost all blue and green wavelengths are cut. You can adjust the filter strength depending on depth or water condition like setting minimum effect near the bright surface while using stronger filter setting at depth with insufficient orange or yellow wavelength.
The product is designed to set minimal filter strength to use with external lighting devices such as a strobe or LED light. For example, shooting wide angle images with ambient light and stronger filter setting, and use minimum filter strength for a macro imaging to use an LED torch.
The filter is equipped with highly versatile screw type M67 Mount.