The  Tiffen Center Spot Filter Âis 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. 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. Clear central area of the filter keeps subjects in the middle of the frame in focus while softening surrounding areas. Helps to isolate subject matter and lessen distracting backgrounds.