What are ND Filters?
Imagine this: you’re at a waterfall and you want to capture an image that would make the water look misty. You know, just like those pictures you see featured in many magazines and other photography sites. So, you set up your camera to take long exposure, but the end result is not the one you desired.
A thought then comes to your mind: How do professional photographers achieve such great-looking photos? Well, the simple answer is that they use what is called a natural density filter or otherwise known as ND filters.
What do ND filters do?
ND filters are designed to reduce the amount of light that reaches the sensor of the camera so that exposure times can be increased without affecting the color of the image.
So, basically, it is your alternative for changing the aperture to reduce the amount of light. Instead, you just add on an ND filter then adjust the exposure to the amount you want.
In short, adding this accessory is an easy and effective method to create professional-looking photos.
How to use ND filters?
You will most likely see a professional landscape photographer armed with an ND filter in their bag. Yes, it may look like a piece of plain, grey glass. But this simple piece can alter your images in many possible ways, especially when you’re capturing photos of moving subjects – people, clouds, water, etc.
Photographing waterfalls is one of the best examples for the use of ND filters. What you get with the filter installed is a sense of movement that is not quite achievable using a regular shutter speed.
With an ND filter, you have the ability to set the aperture and shutter speed you want and not be constrained with what the conditions provide.
ND filters are great to use on a sunny day because they help create a sense of movement. They are even better utilized at night when they can elevate the use of slow exposure to a higher level.
What are the types of ND filters?
There are different kinds of ND filters in the market, and they include:
- circular threaded screw-in filters – very simple to use, but stacking them together creates an issue with vignetting.
- slot-in filters – needs a filter holder attached to lens through a ring adapter then slot square or oblong filters into the holder.
- variable filters – these are more recent and can be screwed right into the lens and has an adjustable outer ring which is used to adjust the density to achieve the effect you want.
ND filters are also available in different strengths which is known as their filter exposure factor. These are:
- 2x one stop
- 4x two stops
- 8x three stops
- 64x six stops
- 1024x ten stops
Basically, as the numbers increase, so does the amount of light they can block. So, the filter you buy depends on how you want to slow things down.[list type=”check”]
When to use ND filters?
- for blurring water motion (oceans, rivers, waterfalls, etc.)
- for reducing depth of field in very bright light
- for reducing the visibility of moving objects
- for adding motion blur to subjects
- for extending time exposures