The Expert Neutral Density Kit includes:
• Cokin Filter Holder
• 4 Cokin Adapter rings (see specs for details)
• Graduated ND4 Hard (2 f-stop)
• Graduated ND8 Hard (3 f-stops)
• Full ND4 (2 f-stops)
• Microfiber Cleaning Cloth
Graduated Neutral Density (ND) Filters allow you to reduce the amount of light reaching the sensor on a portion of your picture. This helps control the exposure difference between Highlights and Shadows for a more balanced exposure and dramatic effect. By rotating the filter-holder and adjusting the position of the filter up and down you can precisely control where the filter has an effect on the image.
Adding a full ND filter allows you to reduce the exposure over the whole image. This helps you reduce shutter speeds to create blurred motion effects in water and clouds as an example.