This B+W Neutral Density Filter reduces the light by six f-stops. With this filter and without changing the f-stop, a shutter speed of 1/60 s is changed to a full second, thus requiring the use of a tripod. Flowing water is rendered as flowing in the photo, and people moving in streets are dissolved in unsharpness or become invisible. Because of its higher transmission in the red beyond 660 nm, this filter brings a slightly warm tone to color photographs. If this effect is undesirable, a B+W UV-/IR-Blocking Filter 486 in front of the neutral density filter (not behind it) remedies that situation. The filter factor is 64x.
Filter Coating: Uncoated Glass
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 our 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 it's 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.