black & white filters

Light yellow (5)
For all outdoor photographs, primarily used as a haze filter with black and white material. Small correction to blue sky, improved contrast in distant photographs.
Exposure factor: 1.5 – 2.0 x (Exp. inc. = – 1)

Medium yellow (8)
Especially recommended for current panchromatic type films. Increases the visible grey tones of green objects such as foliage.
Exposure factor: 3.0 x (Exp. inc. = – 1.5)

Dark yellow (12)
Dramatically darkens the sky and increased penetration of atmospheric haze. Also used for infrared photography for false color photographs.
Exposure factor: 3.0 – 4.0x (Exp. inc. = – 1.5 to – 2.0)

Dark yellow (15)
Control filter for black and white photography. Also used for micro and infrared aerial photography.
Exposure factor: 4.0x (Exp. inc. = – 2.0)

Orange (22)
For increased cloud effects, darkens sky and
lightens clouds. Significant reduction of
atmospheric haze especially when using long
focal length lenses.
Exposure factor: 4.0x (Exp. inc. = – 2.0)

Light red (25)
Used to increase contrast as well as with
infrared film for moon light effect.
Exposure factor: 8.0x (Exp. inc. = – 3)

Dark red (29)
Same as 25 except with a more pronounced
effect. Also used for color separations.
Exp. factor: 8– 12.0x (Exp. inc. = – 3 to – 3.5)

They improve the differntiation of gray tones and optimalized the effect of the pictures.