How Solid Neutral Density Filters Work
Top Reasons to own a ND filter:
- More control over shutter speed and aperture in full sun conditions
- Create motion blur in water, clouds and busy city streets
- Shoot wide open at F1.4 in direct sunlight
- Create dramatic long exposures in any lighting condition
How a ND filter works
Neutral Density (ND) filters reduce the amount of light entering the camera. Often times when shooting a scene, the dynamic range of light supersedes what a camera can capture. In other words, the shadows are too dark or the highlights are too bright for the camera to record all of the information of a scene in a single exposure. A ND filter is essentially a piece of dark glass placed over the lens to “block” or “darken” the brightest areas of a particular scene.
ND filters are manufactured in a variety of ways, all designed to filter light reaching the camera sensor. A quality ND filter allows the photographer more control in selecting shutter speed and aperture combinations that will record a sufficient amount of data to the camera’s sensor.
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.
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:
Neutral Density filters are popular because of their versatility. Almost any situation can necessitate the use of a ND filter. Often times, ND filters are the difference between a good photo and a great one. Below are examples of common situations where a ND filter can be used:
WATER: Moving water can be blurred through a longer shutter speed. It can be helpful to also use a polarizing filter with water to minimize glare and reflection off the surface.
The density of the filter will determine how much to compensate your shutter speed. The more dense the filter, the slower you can make the shutter speed.
CLOUDS: A neutral density filter darkens the scene, and allows a longer shutter speed. Because clouds are moving, the result is blurred clouds that often look smoother and “cleaner.”