Featuring a fully revamped physical design, this 77mm PTC-21 Water-Resistant Ceramic Protector Filter matches the visual identity and pristine optical quality of Sigma lenses. Fashioned from a clear glass-ceramic substrate, the filter offers exceptional impact resistance, with flexibility greater than sapphire crystal. It protects the front element of your lens against dust, dirt, and scratches, and has a water-resistant optical coating that repels liquids.
Sporting an improved surface treatment on its metal frame, the PTC-21 reduces internal reflections, ensuring a clean image and having no effect on color reproduction. The filter is compatible with all Sigma lenses and boasts an improved low-profile design that prevents vignetting; even when shooting on ultrawide-angle glass.