Square and rectangular filter systems solve problems that round, screw-on filters often cannot resolve. To begin with, one square or rectangular filter can be used with many different size lenses. As long as you have the appropriate size adapter rings, in most cases, one filter will serve the purpose.
Another benefit is if you are shooting a landscape where the horizon line is off-center and you want to balance the light intensity in both parts of the scene, i.e. bright sky, shaded foreground . Rectangular filters allow the transition to be blended into the scene, often imperceptibly. This is because they can be shifted up and down in the filter holder to fit the scene as desired. Some graduated rectangular filters are available with soft or hard transitions from dark to clear.
Main features :
High quality aviation aluminum.
Precise CNC machining.
Black frosted surface.
Copper screw plated with black nickel.v Quick installation.
Withstand extreme temperature.
Compatible with 180mm square filters (2mm Thickness).
Allow up to 2 filters to be used together.
Design for use on super wide angle lenses, specifically the Canon EF 11-24 f/4 L USM
No black corners or vignetting.
NiSi 180mm System Aviation aluminum Filter holder specially for Canon EF 11-24 f/4 L USM
180mm system square filter holder is made from aviation-grade aluminum with single element processing by CNC machine.
With matte black frosted finish on the surface.
All of the screw accessories are made of copper and with black nickel plating.
It’s durable and can reduce the influence of stray light on the imaging.