Tiffen Camera Filters manual Sliding Diffusion Filters, Fog, Double Fog and Pro-Mist

enhanced beauty. A first in this field is the fact that the filter is both effective to look at as well as to look through. The filter has a distinct silver sparkle that has been found to be doubly useful. When production starts and people see the glittering on the front of the lens, they become more confident in the knowledge that the filter is working for them and they may also turn in a better performance.

The above types of filters, though most often used for "portrait" applications, also find uses wherever general sharpness is too great, and must be subtly altered.

Sliding Diffusion Filters

When attempting to fine-tune the application of diffusion within a sequence, it can be invaluable to be able to vary the strength of the effect while filming. This can be accomplished by employing an oversized filter that has a gradated diffusion effect throughout its length. It is mounted to allow sliding the proper grade area in front of the lens, which can be changed "on-camera." When even more subtle changes are required, maintaining consistent diffusion throughout the image while varying the overall strength, a dual "opposing gradient" filter arrangement can be used.

Fog, Double Fog and Pro-Mist®

A natural fog causes lights to glow and flare. Contrast is generally lower, and sharpness may be affected as well. Fog filters mimic this effect of atomized water droplets in the air. The soft glow can be used to make lighting more visible, make it better felt by the viewer. The effect of humidity in, say, a tropical scene can be created or enhanced. In lighter grades, these filters can take the edge off excess contrast and sharpness. Heavier grades can create unnatural effects, as for fantasy sequences. In general, however, the effect of a strong natural fog is not produced accurately by Fog filters in their stronger grades That is because they are too fuzzy, with too much contrast, to faithfully reproduce the effect of a thick natural fog. For that, Double Fog filters are recommended.

Double Fog filters have milder flare and softening characteristics than standard Fog filters while exhibiting a much greater effect on contrast, especially in the stronger grades. A very thick natural fog will still allow close-up objects to appear sharp. So will a Double Fog filter. They key to the effect is the much lower contrast combined with a minimal amount of highlight flare.

Pro-Mist®filters generally produce highlight flare that, by staying closer to the source, appears more as a "halo" than will the more outwardly extended flare of a fog filter. They create an almost pearlescent glow to highlights. The lighter grades also find uses in toning down the excessive sharpness and contrast of modern film and lens combinations without detracting from the image. Black Pro-Mist filters also create moderate image softening and modest-to-strong highlight flare, but without as much of a lightening effect on shadows.

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