Shadow areas will reveal more detail but without any flare or halation from direct light sources or bright reflections. The Ultra Contrast works similar to a Tiffen Low Contrast filter with the difference being that it reduces contrast throughout the entire image whereas a Low Contrast filter will only open the shadows.
The #3 Ultra Contrast filter is a grade stronger then a #2. By now, shadow detail is readily apparent. Contrast continues to be evenly lowered throughout the image. As with the other grades of this filter, no highlight flare is produced.
Tiffen's ColorCore glass is produced through a process that entails permanently laminating the filter material in between two pieces of optical glass that are ground flat to tolerances of a ten-thousandth of an inch, then mounting them in precision aluminum rings.
Bright lights or sunlight create problems when the ratio between the highlight and shadow areas is beyond the latitude of the film; if you expose for the highlights, the shadows appear without detail; if you expose for the shadows, the result is washed-out, overly bright highlights
Contrast reduction is achieved by lightening shadows without overexposing or darkening or by darkening highlights without darkening shadows further.
Even direct shooting into the sun produces no flare or halation. Tiffen's ColorCore glass is sealed between two optical glass sheets. In this way, Tiffen can better control the various densities of their filters and thereby create more exact degrees of filtration. This process makes for greater accuracy of color as opposed to glass that is simply dyed and become subject to deviation during the dye process