The HOYA SPECTRAL CROSS filter is made by sandwiching black gauze-like fiber between two pieces of colorless, transparent optical glass in a rotating frame. The results are both soft-focus and cross effects.
The filter creates an overall soft-focus effect for portraits in the studio or outdoors with direct lighting. Back lighting or point light sources at night create heightened cross effects. The effect is somewhat softer than with cross-screen filters. Diffraction of the light produces a slight amount of flare.