Tiffen 72mm UV Protector Wide Angle Mount Filter 72WIDUVP B&H The filter is constructed using Tiffen's ColorCore technology, which involves lamenting the filter material between two pieces of optical glass, grounding flat to a tolerance of 1/10,000th of an inch, and mounting within an aluminum alloy ring. Light-red filter provides the same effect as a Wratten 23A contrast filter, and helps to darken blue tones while lightening warm orange and red tones, when photographing in black and white. There is an approximate 4x filter factor with this filter, requiring an increase of 2 stops for normal exposure. Wratten 23A Equivalent Tiffen 72mm Variable Neutral Density (ND) Filter With Case ColorCore Technology Filter Increasing contrast when working in black and white, this 72mmRed 23A Filter fromTiffen is used to noticeably darken cool and blue tones in order to... Filter factor of 4 requires approximately 2 stops of additional exposure to maintain normal results. Increasing contrast when working in black and white, this Red 23A Filter Âfrom  Tiffen Âis used to noticeably darken cool and blue tones in order to emphasized both shadows and clouds. Buy Tiffen 72mm UV HT Filter Online - Foto Discount World | Trusted Aluminum filter ring is both lightweight and durable., Light red filter
