Star filters create multiple points of light, or "stars," streaking outward from a central light source. This can make lighting within the scene take on a more glittering, glamorous appearance.
This effect is produced by a series of thin lines etched into the flat optical surface of a clear filter. The size and brightness of the star lines produced are first a function of the size, shape, and brightness of the light source. Lee offers 4, 6, and 8 point star effects as well as Selective, Segment, Spot and Graduated Star effects for special situations. With an 8 point filter, the many star lines may tend to overpower the rest of the image, so use it carefully. Generally, mid-range apertures or larger are sufficient to achieve a good star effect.
Lee resin filters are available in 4 x 4" (100 x 100mm) x 2mm thick.
Reviews LEE Filters 4x4" 6 Point/2mm Grid Star Effect Resin Filter