A Coral graduated filter can be used to color balance a portion of the scene, leaving a portion uncorrected (therefore cold or blue). As a color-effects filter, a Coral graduated filter can be used to warm a landscape or enhance an evening sky.
This filter is available in strengths of 1/2, 1, 2, and 3. These strengths achieve a subtle, moderate, or bold effect.
Schneider makes both soft-edge(SE) and hard-edge(HE) Graduated Color filters. Typically, soft-edge filters are used with wide to medium-angle lenses because these lenses have greater depth of field. Hard-edge filters are preferred for use with telephoto lenses or for bold transitions.