# ND filter: density, photo. What is an ND filter for?

Probably, every novice photographer thought about the question, how do professionals capture soft blurry clouds, waterfalls, foggy, as if shrouded in smoke, water streams? At the same time, beginners cannot achieve a similar effect using a slow shutter speed.

This is because professional photographers use ND filters. Do not confuse with gradient filters - they darken only a certain part of the frame.

ND filters are designed to absorb the light that passes through them without affecting color reproduction. This property will allow the photographer to increase exposure time.

The density of the ND filter (the amount of light it transmits) may vary.

 Density The amount of light that the filter passes Exposition ND - 2 // 0,3 fifty 1 ND - 4 // 0.6 25 2 ND - 8 // 0.9 12.5 3 ND - 16 // 1,2 6.25 4 ND - 32 // 1,5 3,125 5 ND - 64 // 1.8 1,563 6 ND - 128 // 2,1 0.781 7 ND - 256 // 2,4 0.391 8

In this article, you will learn how to use ND filters correctly.

## What is an ND filter? A photo

A ND neutral density filter is a translucent piece of glass that attaches to the front of the lens. As a rule, the filter is either colorless or made of gray glass, which blocks a significant amount of light, thereby protecting your pictures from overexposure.

A neutral filter is able to change or decrease the intensity of all colors of light or waves equally, that is, without affecting the color reproduction hue. Therefore, he got his name.

## Where are ND filters applied?

Professional photographers find application for these filters, for example, in bright scenes illuminated by spotlights. The ND filter very effectively prevents the penetration of excess light on the camera matrix, which allows a balanced exposure without compromising color reproduction. He is able to darken the whole scene, returning it to a normal level of brightness, so that the camera will be able to capture it. If you plan to take reflections or take photos on a sunny day, an ND filter is also useful there.

The main goal of this assistant photographer is to allow more flexibility in working with aperture, blurriness of the subject and shutter speed, without taking atmospheric conditions into account. The blur effect created by the ND filter is extremely difficult to recreate even with computer processing of the finished image. And where this becomes possible, processing becomes a very long and laborious process.

## Why are neutral filters useful?

• In order to reduce the depth of field in very bright conditions.
• In order to deliberately create a blur effect when moving various objects.
• In order to increase the shutter speed without compromising the picture.

## How can neutral density filters be used?

In the bag of any landscape photographer you will find an ND filter. However, they are appreciated by lovers much less. Probably because at first glance the ND filter looks like a translucent, darkish piece of glass.

This assistant photographer will not make any visible changes to the resulting frame: he will simply make the image “absorbing” the photosensitive sensor a little less.

However, if you use it when shooting objects in motion, such as a river, clouds, animals, and even people, the ND filter will open up a whole universe of unlimited creative possibilities. By “freezing” the waterfall with an ordinary shutter speed, you get a boring and static image, while using a long shutter speed and a filter, you can get a dynamic picture due to the beautiful blurring of the falling drops.

The flexibility provided by neutral filters can be used in a variety of ways: choose the shutter speed and aperture value at will, without looking at the external conditions that dictate the shooting rules.

If the photo shoot takes place on a sunny morning or in the afternoon, then using an ND filter, you can slow down the movement in order to convey its sensation. However, this assistant photographer helps to get the most spectacular shots at dusk or at dawn. A photographer can buy a little time for exposure - just a few seconds, and at the same time portray the splash of coastal waves with gentle fog.

## Types of filters

Specialized stores are ready to provide photographers with various types of filters. The most commonly used are plate filters mounted on fasteners (holder frame and ring adapter) and having a round thread for installation directly in front of the lens of the lens.

## ND filter: what is it for?

So, we come to the most interesting. How can the ND filter help in the photography process? It has three main functions.

## The first function is slow shutter speed.

Professional photographers with experience gained usually like to take landscapes and nature at long exposures. Photos with “softening” of waves and clouds, washed out water look surreal due to their blur.

If you are interested in the effect of otherworldly and mysteriousness when taking photos, then you need to purchase an ND filter. Using a long exposure requires slowing down the shutter speed, which, in turn, will correctly capture the movement of clouds, water or fog in the frame. However, there is one caveat. In some cases, overexposure may occur due to the fact that due to the slow shutter speed, an excess of light falls on the matrix.

The ND filter that you will use at the front of the lens will block the excess light, allowing you to use a slow shutter speed.

## The second function is to intentionally blur the motion in the frame

A neutral ND filter can also be used when taking photographs when it is important to portray the meaning of movement. So, instead of capturing the movement, as if stopping the moment, the photographer can slow down the shutter speed and use a filter in order to create a blur effect.

## The third function is to reduce the depth of field.

A neutral density filter (ND) can also be used to reduce the depth of field of a photograph. Instead of reducing the aperture, which limits the amount of light entering the matrix, you can add a filter that allows you to obtain selective depth of field and at the same time limit the amount of light. So you can get a photo of a well-selected object, which is located on a beautiful background.

## We buy the ND filter: what needs to be considered?

Many photographers are wondering which ND filter to choose. What characteristics do you need to pay attention to? We will tell you now!

## Materials and Coatings

Several factors affect the quality, and hence the cost of the filter. Such are the material from which the accessory for the camera is made, and its coating. The ND filter can be made of resin, glass or polyester. The cheapest of these materials is the latter. However, it also distorts the light transmitted through itself to a greater extent.

There are many different types of coatings that successfully reduce the effect of doubled image and flare, while black aluminum holders with tinted glass help reduce vignetting.

## Plate filter or threaded filter: which one to prefer?

Round filters are small in size, easy to install, but lack the important criterion - flexibility of use. Often a combination of several filters leads to a problem with vignetting, while a particular filter is suitable only for a certain diameter of attachment to the lens.

To use square plate filters, you will need a frame holder and a ring adapter. These accessories must always be carried with you.

It’s not so convenient to deploy a system for installing square plate filters, but it will allow you to quickly and easily combine filters. As a result, you will significantly increase the exposure time.

The main and main advantage of the plate filter is that it can be quickly replaced or combined with some other one by installing several plates at once. Moreover, such a combination may include not only one specific, but also several types of filters. You can combine ND plates with other types of filters, for example, polarizing or neutral gradient.