Sigma 67mm EX DG, Digitally Optimized, UV (Ultra Violet) Wide Angle Multi-Coated Glass Filter

Digitally Optimized (DG) Filters
Ex DG filters benefit from Sigma's multi-layer lens coating, developed to counteract the highly reflective characteristic of image sensors. With older style filters, light would reflect off the image sensor, bounce off the lens and filter elements and re-enter the image sensor, creating a ghost image. The multi-layer coating dramatically reduces this effect. In addition to this, an optimum, neutral color balance is ensured, increasing the white balance accuracy of the digital camera.

Multi-coated UV Filter
This filter perfectly eliminates the harmful effect of ultraviolet light. The multi-coated UV filter can be used with both color and black-and-white film and digital sensors. This is the most suitable filter for protective use and general photography.