Tiffen 52mm Ultra Contrast 3 Filter

Controlling contrast is difficult in bright sunlit exteriors. Exposing for either highlights or shadows will leave the other severely under-or over-exposed.

Low Contrast filters create a small amount of "localized" flare near highlight areas within the image.  This reduces contrast by lightening nearby shadow areas, leaving highlights almost unchanged. 
 
Soft Contrast filters include a light absorbing element in the filter which, without exposure compensation, will reduce contrast by also darkening highlights.  Use this latter filter when lighter shadows are not desired.  In both cases, the mild flare produced from bright highlights is sometimes used as a lighting effect.

Ultra Contrast Filter
Tiffen was recognized with a Technical Achievement Award from the Academy of Motion Picture Arts & Sciences for the innovative design of this popular Motion Picture and TV filter.
It uses the surrounding ambient light, not just light in the image area, to evenly lighten shadows throughout.  Use it where contrast control is needed without any other effect on sharpness or highlight flare being apparent.

Features

• Works with surrounding ambient light
• Captures details lost in shadows
• Lowers contrast evenly throughout image
• No flare or halation
• Lets you "see" more