Formatt 138mm Cool Day For Night 2 Filter

Benefits

Each filter is manufactured from Schott-Desag B270 Crown Optical Glass

Absolute consistency in color and density to Kodak Wratten standards

Precision grinding and polishing result in unbeatable optical flatness allowing use on even ultra-long focal length lenses

Filter edges are protected with a unique frame for maximum protection and easy handling

Absorbing Cell Technology

The secret to Formatt's consistency in filter design lies in its unique "Absorbing Cell Technology" (A.C.T.); this unique process allows color correct dyes to be applied to optically pure, wafer thin absorbing cells and offers a controllability that ensures the smoothest grad lines and consistent color across the whole filter surface.

This process is revolutionary compared with conventional filter dying techniques by eliminating the need to directly coat the glass surface itself; the repeatable performance gained through A.C.T. ensures that at any time you have to swap like filters for like filters mid shoot you can do so with confidence with no discernible differences in color or density.

Each filter is guaranteed flatness to a maximum 2-wave value and comes with an individual reading from a laser interferometer; every filter is carefully verified with a densitometer and spectrophotometer to ensure consistent and accurate transmission, before leaving the factory - the result is an absolute purity of image that eliminates any unwanted colorcast caused by conventional greenish soda-lime glass.