What is Graduated Neutral Density (GND) Filters?
One of the biggest challenges when shooting is to manage the light in your scene. Graduated ND filters are commonly used where there is a large contrast between the brightest parts of a scene and the darkest part of a scene.
What is a Graduated Neutral Density Filter(GND filter)?It is a rectangular, optically correct piece of resin or glass with a gradient from dark to light. The darker part can block some light entering the lens. You can get different exposure values in one single frame. So the different parts will get different exposure values.
What is a GND filter used for?If you intend to expose the scene without using an ND grad filter, very often, the foreground would be well exposed while the sky may simply be overexposed or, if you intend to expose for the sky, the foreground would be dark. When using the GND filter the details of both sky and land can be properly captured.
Types of GND filters
Usually defined by no obvious transition between the bright and dark area of the scene. Soft GNDs are therefore used where the transition between light and dark areas is not so clear. An example is a shot in a mountainous area, or trees, etc.
Usually defined by an obvious boundary between the bright and dark area of the scene. They are therefore used when the separation between the bright and the dark areas of the scene is very defined, such as the horizon line or the boundary between sea level and the sky.
Reverse GNDs are basically Hard GND filters with the darkest fading away the further you move from the line of separation to the upper border of the filter. They are perfect for managing sunrises and sunsets, where the light is more intense on the horizon line. If you love shooting sunrise and sunset this filter is a must-have.
When to use GND filters?Normally a GND filter can be applied in several scenarios :
1: At sunrise/Sunset
2: At the beach or seashore
3: the sky and land landscape photography in the day time
4: Maintain some bright part details
All in all, if you find the light contrast is strong, and the image can only present some details (only can capture dark part details or light part details). This is the time when a GND filter plays a role.
From this image, if not using the GND filter, above the pic, the ground will be dark when keeping the sky detail. GND filter balances the light and makes the image sharper.
How to use GND filters?GND filter is easy to use. Thread the proper filter on the lens.
If the contrast is strong (the harsh sunlight) then using more strength of the ND filter. Normally ND4 or ND8 will be enough for most shooting situations.
Let’s check 4 stops and 8 stops of GND :
Using a GND filter to slow down the shutter to get the silky water effect.