Simply mount the filter on your lens, set it to "Min" density then frame and focus. Care must be taken with focusing at heavier densities to make sure focus is accurate. However, if it isn't, switch to manual focus and rotate to the desired degree of filtration.
For example, if your standard exposure without the filter is 1/500 @ f/8 and you then set the filter to "Min", you change the shutter speed to 1/125 at the same aperture - thereby losing 2-stops of speed while gaining a hint of "blur" in the image. If that's not enough filtration, continue rotating the filter until you reach the shutter speed you desire. Using the above example, you can even get down to 1/8 second @ f/8 (8 stops). It should be noted that the calibration marks on the filter ring are to be used only for reference and should not be regarded as accurate settings for specific densities.
A Neutral Density filter is used to create some unusual special effects such as capturing the "blur" of the rippling water of a waterfall or the swirling effect of city traffic. Since it allows the use of slower shutter speeds in bright light, it becomes possible to create these special effects that would normally not be possible to capture without the filter. And, since it can also help to control your depth of field, it permits you to shoot at wider apertures. Ultimately, its value is in helping to prevent bright, overly washed out images shot in bright light.
This filter is made using ColorCore technology, a process that involves laminating the filter substrate between 2 pieces of optical glass, grinding flat to a tolerance of 1/10,000th of an inch, and then mounting to precision metal rings.
The ColorCore process allows Tiffen to control the color and density of their filters, and the characteristics of special effects filters with much greater accuracy than typical dyed-in-the-mass filters, which usually exhibit color and density variations. In this way, Tiffen can better control the various densities of their filters and thereby create more exact degrees of filtration.
Neutral Density Filters Have Four Main Uses
Made in the USA!