B+W's 60mm Star Cross Screen 688 8X Filter produces a 8-point star effect. Like two 4-beam star screens superimposed at a rotational angle of 45°, this star screen generates eight star beams. Therefore there should only be a few light sources within the image area and the background should have large dark areas in order for the star beams to remain recognizable.
This filter is uncoated. Uncoated glass is usually found with special effects filters and acrylic filters, where coating is either an impossibility or would work against the effect the filter is trying to attain.
This filter uses the standard B+W F-Pro filter mount, which has a front accessory thread and is made of brass. Compared to the earlier standard mount introduced in 2001, the F-Pro mount has become thinner. Now it can be used with wide angle lenses, including most 24mm focal lengths on a full frame body, without vignetting. Another advantage of the F-Pro mount is its modified retaining ring, which is no longer threaded in from the front, but holds the filter glass in place from the back. When removing a filter or lens hood that has been screwed on too tight to the filter, the retaining ring is not at risk of loosening.
Note: diopters are mounted in the older mount due to glass thickness.