The Cokin A120 filter allows you to darken part of the image by 1 and 2/3 of the aperture (ND3,3), while the rest is completely neutral. It is used most often when we want to align exposure or highlight some part of the frame. Cokin filters are mounted using a holder (holder), which is attached to replaceable mounting adapters, with diameters that can be adapted to your lens. System A (size S) is recommended for use with compact cameras with lens filters or amateur video cameras.