Hoya Variable Density II variable ND filter (3-400) 77mm

HOYA Variable Density II is a variable density filter with an ND range of 1.5 to 9 f-stops (ND3-400). The difference from the previous HOYA Variable Density filter is the new rotating frame with a convenient adjustment knob, which provides better usability.

Variable density filters are widely used because they can replace a whole set of fixed ND filters by providing a range of density that can be adjusted to the desired exposure settings. In photography, variable density filters reduce the shutter speed according to the photographer's intent when the shutter speed cannot be reduced due to camera limitations. Variable density filters can also increase the bokeh effect when shooting in excessive light, thus preventing the image from being overexposed.

In video recording, it is essential that the shutter speed matches the frame rate - that is, it should be equal to double the frame rate for optimal results. Unlike in photography, a shutter speed that is too fast can create a distracting effect and afterimages that will not look good in the final video. With variable density filters, the shutter speed can be adjusted to the correct value.