It generates a very low refractive index of 1.46 and offers excellent temperature stability. The redesigned brass filter frames can be easily screwed on and are designed to withstand the toughest adventures. With optical coatings for a neutral colour profile and multiple coatings for improved scratch resistance, water resistance, anti-reflection and reduced vignetting in wide-angle shooting, the QuartzLine filter lets you take pictures with lifelike colours - even in the most extreme locations around the world. It comes with a microfiber lens cloth, soft filter pouch and filter sleeve. A neutral density (ND) or gray filter blocks some of the incident light. With a grey filter you can extend the exposure time considerably and thus achieve effects such as blurred water or prevent overexposure of the image in the midday sun with the aperture open.