ABOUT ND FILTERSNeutral density (ND) filters are the most demanded and essential type of photographic filters because of several reasons. For photographers ND filter means precise control of the amount of light passing through the lens for greater creative control over exposure. For video content creators ND filters help much to set shutter speeds to match the frame-rate while maintaining the depth-of-field of the footage.Light density filters will lower the shutter speed in the bright sunny day to allow you to reduce depth of field in very bright light or to use a wider aperture to stay below the diffraction limit. For example, these filters are necessary to shoot with your fast lenses like F1.4 or F1.2 with aperture wide open for softer and more beautiful bokeh.COLOR SHIFT ISSUE SOLUTIONHOYA of/ers its own exclusive and wide lineup of ND filters that are ed into PROND EX series for both photographers and filmmakers. PROND EX filters adopt HOYA's clear optical glass that is mounted into a lightweight, precisely crafted aluminium frame. The frame has front filter threads so you can attach additional filters or a lens cap.Thanks to ACCU-ND technology that puts HOYA ND filters far ahead from other s the image undergoes no negative effect from colour shift that may occur due to low-quality materials, poor manufacturing QC, or issues with leaking of the Infrared band of the light spectrum. The last problem is the most important nowadays in photography and videography.HOYA's exclusive ACCU-ND technology achieves equal reduction of the light in visible and IR spectrums. As a result the photographer may not fear any issue with colour shift when using HOYA ND filters in different shooting conditions.