ISF FSN 67mm square filter for Pro4 and Cokin A series holders. This is a Neutral filter offering a Gentle full frame softening effect making it ideal for professional quality portrait and wedding photography. Place the filter close to the lens as possible for best effect. Use on lenses between 35 and 70mm on 35mm format and full frame digital, or 60 and 100mm on medium format. using aperture between f/2.8 and f/5.6
marks around edges where it's been inserted in filter holder, no affect on photos.