Hoya Spectral Cross is a filter made by sandwiching black gauze-like fiber between two pieces of colorless, transparent optical glass in a rotating frame. Spectral Cross Filter produces both soft focus and cross effects. An overall soft-focus effect is obtained for portraits, etc., outdoors with direct lighting, while back lighting or point light sources at night create heightened cross effects. The effect is somewhat softer than with cross screen and diffraction of the light produces a slight amount of flare.