How Center Graduated Neutral Density Filters Work

How a Center Graduated ND Filter is Made:

Reverse Graduated ND filters are not the same as solid ND filters in that they have a gradation of darkness that starts on one side and ends on the other. Reverse Graduated ND filters are similar to Graduated ND filters but the gradation goes in reverse:

Field of View - How to Determine the Right Size Filter:

Cokin square filters are manufactured in three sizes. The size of filter and corresponding adapters you decide on will depend on a number of factors. The most important thing to determine is your field of view. You want to have a filter that will ultimately cover the range of your widest focal length:

 

If your 16mm lens is wider than what the filter can cover, then you will see vignetting and/or the filter holder in the final image.

Here are some other features to look for in deciding which ND filter is best for you: 

• Color Shift: Should be non-existent or at minimum predictable results
• Vignetting: A quality filter does not amplify vignetting from a lens.
• Durability: Filter is resistant to inevitable dings and knocks
• Simplicity: The system is easy and quick to set up and use on location and/or during a shoot. 

When to Use it:

When the sun sets near or on the horizon line, it creates a bright area along that line. This is an opportunity to use a center graduated filter to control the extreme brightness.

These examples were created using the Nuances Graduated Neutral Density Filters. The Nuances GND lineup is manufactured with hardened, tempered optical glass. The G2 series is manufactured with optical resin.