If you've invested a small fortune in lenses then you probably want to give them the best protection possible. You could do that with a solid off the shelf protective filter, but we have a feeling none of those options will come close to Sigma's new ceramic protectors. What makes it better? The clear glass ceramic is 10x as strong as traditional filters and 3x as strong as chemically hardened glass. It's also water-repellent and reduces any potential ghosting.