Graduated Neutral Density (GND) filter, is a rectangular filter that increases the dynamic range of your camera. Shooting a sunset with a GND filter transforms a photograph from having blown out Bullets to one with incredible dynamic range, and it does this in-camera, without the need for Photoshop, stacking multiple frames or HDR. 

The X4 GND is the world's first GND to use tempered glass, the result is the most durable GND on the market. By using SCHOTT B270 optical glass made in Germany, the X4 GND resolves critically sharp.  

Our state-of-the-art multi-resistant coating (MRC) is an optical coating applied to both surfaces of the glass disk to reduce reflection and to increase surface durability. Our proprietary MRC coating is structurally harder than the glass itself and the reduced reflections improve the efficiency since less light is lost. The reduction of reflections also improves the contrast of the image by elimination of stray light. The real world result? Better contrast and colour. 

Low light transmission and green flaring are common problems with traditional CR-39 resin GNDs. As MRC coatings are added to each side of the optical glass light transmission steadily increases with flaring steadily decreasing. In our lab tests light transmission apexes at about 16-layers of MRC, and slowly decreasing in transmission at 18 and above. 8-layers of MRC are applied evenly to both sides of each optical disk resulting in MRC16. 

Specs 
Glass Type - Tempered SCHOTT B270 Optical Glass 
Filter Type - Graduated Neutral Density 
Filter Factor (Light Reduction) - 2 stops / 3 stops 
Graduation Type - Soft / Hard / Hard Reverse 
Filter Sizes - 100x150mm, 150x170mm 

Packaging Info 
100x150mm - Package Weight -  9.6oz 
- Box Dimensions (L x W x H”) - 7.75 x 5.75 x 1”