Tiffen Camera Filters Brochure page 8

attention to the presence of the filter, especially with stronger grades, when diffusion is not
required elsewhere. It may be desirable to lightly diffuse adjacent scenes or subjects, not
otherwise needing it, to ensure that the stronger filtration, where needed, is not made
obvious.
In diffusing faces, it is especially important that the eyes do not get overly soft and
dull. This is the theory behind what might be called circular diffusion filters. A series of
concentric circles, sometimes also having additional radial lines, are etched or cast into the
surface of a clear filter. These patterns have the effect of selectively bending light in a
somewhat more efficient way than nets, but in a more radial orientation. This requires that
the center of the circular pattern is aligned with one of the subject's eyes, not always an
easy, or possible, task, to keep it sharp. The rest of the image will exhibit the diffusion
effect.
A variation on the clear-center concept is the Center-Spot filter. This is a special
application filter that has a moderate degree of diffusion surrounding a clear central area
that is generally larger than that of the circular diffusion filter mentioned previously. Use it
to help isolate the main subject, held sharp in the clear center. while diffusing a distracting
background, especially in situations where a long lens and depth-of-field differentiation
aren't possible.
Another portrait diffusion type involves the use of small "dimples," or clear refracting
shapes dispersed on an otherwise clear optical surface. They can be round or diamond-
shaped. These are capable of more efficient selective diffusion than the net type, and have
no requirement to be aligned with the subject's eye. They don't lower contrast, as by tinting
shadows, as light-colored nets do. These dimples refract light throughout their surface, not
just at the edges. For any given amount of clear space through the filter, which is relative
to overall sharpness, they can more efficiently hide fine details than net filters. A more
recent development, the Tiffen Soft/FX® series involves a minutely detailed series of
patterns, made up of tiny "lenslets," each with a greater degree of curvature, with more
optical power, than that developed by the dimples previously mentioned. This produces a
maximum of selective diffusion efficiency for any given amount of overall sharpness.
Taking diffusion to yet another level, where keeping the existence of the filter from
being readily apparent to the viewer is of paramount importance, is the Diffusion/FX®
Series of filters. Available in Black and Gold Series, these are a combination of finely
etched surface texture, with a unique pattern that maximizes the ability to reduce wrinkles
and other fine details, with an internal pattern of very fine dots, which add subtle edge-
diffraction effects. In addition, the Gold Diffusion/FX also incorporates a mild reduction of
contrast, and a subtle gold "warming" tint, for improved skin tones.
The Glimmerglass is the first series of filters with a 'psychological edge.'" Tiffen has
developed the Glimmerglass series of filters for "making people look their best." A new
type of diffusion filter, the Glimmerglass subtly softens fine details in a unique manner,
while adding a mild glow to highlights. As contrast is also reduced, the look is one of
CAMERA FILTERS © Ira Tiffen
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