Tiffen Cokin P ND 0.9 Glass Filter (3-Stop)

Determining which neutral density filter yields ideal results for any given lighting situation takes knowledge, experience, and a collection of such filters. Choose the filter strength that adjusts the lighting to stay within the exposure latitude (greatest difference between bright/dark values) that still shows details in both the digital or film medium in use.

Speaking generally, the 2-stop value (ND 0.6a the filter s clear portion allows 4x more light to pass vs. darkest portion) effectively compensates average situations.

When more precise lighting control is required, Tiffen also makes a series of graduated neutral density filters. These filters permit better exposure balance between bright skies and darker foregrounds or vice versa.

Neutral Density Filters Have Four Main Uses

To enable slow shutter speeds to be used, especially with high speed films, to record movement in subjects such as waterfalls, clouds, or cars

To decrease depth of field by allowing wider apertures to be used, which helps separate subjects from their backgrounds

To decrease the effective ISO of high speed film (above ISO 400) and allow it to be used outdoors in bright situations

Neutral Density Factors

ND 0.3 (exposure adjustment = 1 stop, reduces ISO 1/2)

ND 0.6 (exposure adjustment = 2 stops, reduces ISO 1/4)

ND 0.9 (exposure adjustment = 3 stops, reduces ISO 1/8)