NiSi 6729 100x150mm Reverse Graduated ND8 Filter

The NiSi 6729 Reverse Graduated ND8 fills a very specific gap in the landscape photographer's filter kit. Standard hard-edge GNDs place the greatest density at the top of the frame and lighten downward — a logic that works beautifully when the sun is overhead but breaks down the moment it drops to the horizon. That's precisely when the reverse GND earns its place: the 3-stop density peaks at the midpoint transition and softens both upward and downward, balancing the blinding brightness of a sun sitting right on the horizon line without crushing the upper sky or washing out the foreground. For coastal shooters, alpine ridge-line work at dawn, or anyone chasing that first and last light of the day, this is a technically necessary tool rather than a luxury upgrade.

Build quality aligns with what NiSi has established across their 100mm system. The glass is optically flat, ground to 2mm thickness for compatibility with standard 100mm holders, and finished on both faces with their Nano coating — waterproof enough to handle sea spray, anti-reflective enough to suppress flare from the near-horizon sun you're deliberately shooting into. The filter slides into any 100mm-compatible holder without flex or rattle, and the hard transition line is sharp and repeatable, which matters when you're repositioning quickly as light changes. At 100x150mm it's a substantial piece of glass, but that size is the minimum needed to cover wide-angle focal lengths without vignetting — a practical engineering choice rather than an oversight.