Characterized by its uniquely durable construction, the 77mm WR Ceramic Protector Filter from Sigma is a clear filter designed to guard the front of a lens from impacts, scratching, and other elements. Developed using a clear glass ceramic substrate, this filter blends a high 99.76% transmittance value with greater hardness than chemically-strengthened glass and greater flexibility than sapphire crystal glass. This results in a build that is shock- and scratch-resistant to withstand a variety of impacts while shooting. Additionally, a water-repellent coating has also been applied to resist water droplets and fingerprint smudging, as well as static electricity from attracting dust or other particles. Built for use in trying conditions, the unique design of the WR Ceramic Protector Filter helps to maintain the lens' inherent image quality while affording a high degree of protection.

Clear Protection Filter    Prevents Damage to Lens    1x Filter Factor, +0 Stop    99.76% Transmittance    No Effect on Image    Clear Glass Ceramic Construction    Scratch- and Shock-Resistant    Water-Repellent Coating    77mm Front Threads    Durable Acrylic Filter Case

Clear protection filter guards the front lens element from a variety of impacts and scratching without affecting image quality.

Clear glass ceramic is a highly durable substrate that has a greater hardness than chemically-strengthened glass and more flexibility than sapphire crystal glass.

Unique construction has a Vickers hardness number of 700HV, making it both scratch- and shock-resistant. This hardness also lessens the likelihood of scratching or chipping that can lead to the filter shattering.

Rather than only the surface structure being hardened, clear glass ceramic involves a heat treatment process that precipitates microcrystals of a mineral called spinel in order to achieve consistent, even strength across the entire filter surface. This strength also enables the design of the filter to be notably thin and lightweight.

A water-repellent (WR) coating has been applied that, in addition to preventing water and oil from adhering to the filter surface, also helps to minimize ghosting and flare. This coating reflects 0.24% of light, giving an overall transmittance value of 99.76%.

The WR coating also serves as an anti-static coating, which helps to repel dust or other particles from clinging to the filter surface.

The included hard acrylic case protects the filter when not in use and has been designed to prevent accidental, unwanted opening.

Related Questions and Answers

Q: 1. Hello, does it fit to the Nikon AF-S 24-70 f/2.8E ED VR?

A: Yes, the Sigma 82mm WR Ceramic Protector Filter can fit the Nikon AF-S NIKKOR 24-70mm f/2.8E ED VR Lens.

Q: 2. Real-life experience comparison regarding the 'water repellant' coating of this filter vs., say, the B + W circular pola? Any difference in environments with rain/snow/humidity? Thanks.

A: Yes, the water repellent works quite well when it comes cleaning the filter without leaving streaks,etc...,as well as not fogging up.

Q: 3. Will this work with a Lee Foundation Holder or a Cokin Z-Pro holder?

A: Unfortunately no, this filter will not work. Those filter systems require square or rectangular filters.

Q: 4. Is the filter frame aluminum or brass?

A: The ring on this filter is aluminum.

Q: 5. How effective is the hydrophobic treatment? Presumably a titanium oxide coating?

A: Hydrophobic and oleophobic coatings on glass elements and filters such as the Sigma 95mm WR Ceramic Protector Filter (B&H# SICGC95) are typically fluorine-based rather than titanium-based, as the later would block much visible light. It causes most water to bead and roll off if there is any incline to the angle at which the filter is held. When dealing with water droplets and splashes, I have found this type of coating sheds most water without my needing to address it at all. When a water droplet does not roll off right away, I just blow on it to shed it without having to take a break to wipe the lens or filter. I do not need to touch the element at all and I'm immediately back to shooting.

Q: 6. If you place the 82mm filter on the RF 85mm 1.2L, can you still attach the lens hood?

A: The Canon RF 85mm f/1.2 L USM Lens has not been tested with that specific filter but it does work with most with the hood attached. The hood will not work with most polarizing filters.

Q: 7. Will this vignette with an 18mm lens? Specifically the Tamron 18-300 (67mm). Any issues with the hood fitting properly?

A: This filter will not vignette unless it's wider than 16mm on a full frame camera. You shouldn't have any issues fitting the lens hood over the filter either.

Q: 8. How thick is the filter ring?

A: The ring itself measured 4mm. That is how much it will be after screwing onto the lens.

Q: 9. Is there any quality degradation on 150-600mm lens, at focal lenghts beyond 200mm?

A: The Sigma 95mm WR (Water Repellent) Circular Polarizer Filter would have the same effect on the lens at all focal lengths. While adding any optic in front of the optical formula of your lens will have some amount of effect to your lens' image quality, the Sigma 95mm WR (Water Repellent) Circular Polarizer Filter is a high-quality filter, and the benefit of its circular polarizing performance in reducing glare/flare from non-metallic items, increasing contrast/saturation, and deepening the blue hue in the sky (depending on your orientation to the sun) would mitigate any minor negative degradation you would obtain from using the filter on your lens.

Q: 10. why am I having problems with scratches on the glasswhy am i getting scratches on the glass?

A: A filter like a lens is still glass and is sensitive to scratches like any other lens.Some filters are better than others. But a lens cap still needs to be used when using filter to protect it when you put it in a camera bag.