Polarizing filter
Minimizes reflections in non-metallic surfaces, such as water and glass. You can, for example, photograph through a window without any disturbing reflexes from the surroundings. The filter can also be used to increase color saturation. A blue sky becomes even more intense and makes white clouds stand out, like in travel brochures. The that a polarizing filter provides can not be simulated with any software filter effects.
Graduated ND Filter
The Graduated Neutral Density filter (NiSi Medium GND 0.9) is used to darken a sky that may otherwise become too bright in the image. It brings out cloud formations and color shades that the camera otherwise cannot display.
The upper half of the filter is dark gray, which gradually becomes more and more transparent towards the middle. By sliding the filter up or down in the holder, you can place the gray part exactly right over the sky.
NiSi Starter Kit