The Kenko ND Professional Series is a high precision ND filter with a special multi-layer membrane using vacuum vapor deposition technology. It has a reduction in the amount of light without affecting the color of the photograph. Use it when you want to shoot slow shutter or when you want to shoot at a bright aperture.
The ND Professional is a ND filter series for large caliber 86mm and above. Choose from 4 concentrations of ND2, ND4, ND8, ND16. Exposure multiples are as follows:

■ ND2 Professional N: Exposure multiples 2 (1 aperture reduction)
■ ND4 Professional N: Exposure multiples 4 (2 aperture reduction)
■ ND8 Professional N: Exposure multiples 8 (3 aperture reduction)
■ ND16 Professional N: Exposure multiples 16 (4 aperture reduction)