The Singh-Ray 72mm LB ColorCombo Polarizer Filter blends both the LB Color Intensifier and LB Warming Circular Polarizer into a single filter to provide the benefits of both in a more convenient package.
The LB Color Intensifier aspect is designed to enrich local color contrast in specific regard to warm colors as well as greens. The filter strives to boost the intensity of those specific colors while maintaining a natural rendering of other neutral colors as well as white tones within the scene.
The LB Warming Circular Polarizer portion of the filter helps to reduce reflections and glare by filtering out light that has become polarized due to reflection from a non-metallic surface. This results in a noticeable increase in the saturation of skies and foliage, as well as clearer imagery when photographing in hazy conditions. A circular polarizer differs from a linear polarizer in that it supports full use of a camera's autofocus and auto exposure functions. Additionally, a warming effect is applied to imagery by imparting a slight red/yellowish hue across the entire image.
The LB designation of this filter stands for "Lighter, Brighter", which refers to the lower optical density of the filter that enables shorter shutter speeds or smaller f/stops to be used when the filter is in place. The brighter design of the filter also enables a brighter viewfinder image to aid in composition as well as improves auto exposure and focusing performance. This filter requires an additional 2 stop exposure for normal results.
Singh-Ray ring-mounted filters are constructed from highly polished proprietary glass to provide notable image quality and clarity. The standard ring mount design measures 8.5mm-thick and features front filter threads for stacking of additional filters.