The Heliopan 37mm KB-1.5 (82A) Filter is a color conversion filter that helps to slightly increase color temperatures and provide a cooling effect. The 82A removes the yellow light cast that commonly occurs in the morning and evening hours. It provides an increase of about 200K.
There is a 1.3x filter factor with this filter, requiring an increase of 0.3 stop for normal exposure. It has a 37mm brass mounting ring that is painted a matte black to help reduce reflections. The SH-PMC multi-coated Schott glass provides greater contrast and reduced reflection compared to uncoated filters.