The Cokin NX System is designed to work with super-wide-angle lenses up to 16mm wide and hold a circular polarizer and (2) 100mm wide square or rectangular filters without vignetting. Vignetting, or darkening of the corners is caused when you start adding holders and filters to the front of the lens, causing the camera to see them. The most common ways to solve this problem are to use fewer filters, or larger ones. Cokin designers were determined to engineer a thin but strong aluminum holder that maximizes functionality in the least amount of space while using common 100mm wide filters* like Cokin's Nuances Extreme Neutral Density series. The NX holder cleverly houses the dedicated all-glass Circular Polarizer within the skeletal frame, yet is easy to mount and remove without touching the glass. Polarization is controlled by spinning a wheel on the outside of the holder. This means the polarizer does not add extra bulk to the system when it is used. Next, they opted to eliminate the traditional filter slots that waste space between filters for micro ball-bearings on the inside of the holder. These bearings are precisely positioned to accept the small grooves on the sides of the NX filter frames designed exclusively for the NX system. The all-aluminum, lightweight NX filter frames provide two specific benefits: 1- They protect the sides and corners of your glass filters and allow you to handle them without touching the glass. 2- They make it possible to stack the filters directly on top of each other which reduces bulk and prevents stray light reflections. All of these carefully considered design elements allow photographers to use 100mm wide filters* with super-wide angles like the Sony and Canon 16-35mm lenses without vignetting. The NX holder requires a L-series / Z-pro adapter ring that screws onto the lens' filter threads. These are the same filter rings Cokin has used for decades and they are available with 49mm-95mm threads. *Cokin NX System is compatible with these filters: • Cokin Nuances Extreme Neutral Density and Graduated ND Filters (Z-pro / L-series sizes) • Cokin Nuances Clear Sky and Infrared IR72nm (Z-pro / L-series sizes) • Other manufactured square and rectangle filters measuring 100mm x 100mm x 2mm thick and 100mm x 150mm x 2mm thick (please refer to the original manufacturer for your filter's exact measurement and thickness) *Cokin NX System is not compatible with: • Original Cokin Nuances Neutral Density and Graduated Neutral Density Filters • Cokin Creative filters (resin type) • Filters that do not measure exactly: o 100mm x 100mm x 2mm o 100mm x 143.5mm x 2mm o 100mm x 150mm x 2mm