Cross Screen Filter
A cross screen filter, also known as a star filter, creates a star pattern, in which lines radiate outward from bright objects. The star pattern is generated by a very fine diffraction grating embedded in the filter, or sometimes by the use of prisms in the filter. The number of stars varies by the construction of the filter, as does the number of points each star has.
Also known as: Star Filter
I love to use this filter for night time shots of the city. It really makes the lights on the buildings really pop out. Plus you don’t have stop down the aperture all that much on the lens in an already dark scene.