Cokin H220 Black & White Filter Kit P series (Filter Holder, Yellow #P001, Red #P003, and Green #P004)
P001 - Yellow
Commonly used for a noticeable increase in contrast with black and white films. Especially useful for clear contrast between blue sky with clouds and foreground. It is also suitable for landscapes and nature scenes.
P003 - Red
Red filter is ideal for strong contrast improvement since it absorbs green and blue completely and enhances red. Clouds are dramatically improved almost to the mood of a thunderstorm. It is more effective in cutting through haze, and moonlight effects are easily accomplished. It is also suited for infrared photography.
P004 - Green
Green filter is ideal for scenes where it is important to differentiate the green tonal values in black and white photography. The application is especially suited to landscape photography because it enhances the light green color of the leaves. Due to its favorable effect on red tones, it is also suitable for portraits.