The Tiffen 105mm Coarse Thread Warm Center Spot Filter is a softening filter that allows you to maintain sharp, clear focus in the center of the image while blurring the perimeter of the frame. This helps to isolate your central subject matter while softening the surrounding areas.
This filter also combines the diffusion effect with an 812 warming filter for providing a general warmth to the image and for improving skin tones. This warming effect also helps to reduce blue sensitivity and for cutting through overly cool tones within the scene.
Tiffen filters are made using ColorCore technology, a process that involves laminating the filter substrate between 2 pieces of optical glass, grinding flat to a tolerance of 1/10,000th of an inch, and then mounting to precision metal rings.