Sigma 46mm EX DG, Digitally Optimized, Circular Polarizer 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.

Wide Multi-Coated Circular PL
It reduces the glare and reflections from glass and water and other non-metallic surfaces. It deepens blue skies, and saturates the colors. The Sigma circular PL filter is designed to give best performance with AF Cameras. You can monitor the changes at different angles through the viewfinder as you rotate this filter.