Boxed. Like the Y48 and Y52, the Y44 Light Yellow Filter absorbs both the blue and ultraviolet light, so that skies appear darker in a B&W print. These yellow filters are particularly useful for heightening contrast. Mild filter Y44 and medium filter Y48 are best suited for portraits and snap shots whereas the Y52 offers the strongest effects and is commonly used for landscape photography.
As the filter factor increases, the colour deepens and the effect becomes more pronounced. Filter/exposure factors are: Y44 = 1.5; Y48 = 1.7; Y52 = 2.