What is an ND Filter? What does it do, how does it work on the camera?

The ND Filter is a familiar part on the camera that helps to take more effective photos. So what is an ND Filter, and how does it work on a camera? Let’s find out with Tnhelearning.edu.vn!

What is an ND Filter?

An ND filter is a camera supplement optical device , consisting of a layer of glass that reduces light intensity to the camera’s sensor, helping us to extend the time of taking pictures under strong light sources.

What does ND Filter do?

Filming to blur the background

To capture the best video possible, you want to blur the background and need to keep the camera aperture open. However, with a large aperture, the amount of light often leads to overexposure. And you need to use an ND Filter attached to the lens to reduce the amount of light passing through the lens to the sensor.

Reduce light intensity

Reducing the intensity of light that is too strong causes blurred images when shooting in backlit, reducing the shooting time so that the camera does not have to shoot too quickly beyond the limit of the device, making the image clearer and showing better details.

Exposure photography

When taking an exposed photo, the camera’s shutter stays open longer to capture the image and light entering the sensor. Exposure works will give us a very fancy and smooth image, the longer the exposure, the smoother the image will be, but if you don’t control the amount of light entering the sensor, the final image will happen.

• Low light photos : When exposed, the light sensitivity (ISO) will be at the basic level, if the shutter is not open for long enough , the image will not be bright and smooth, we will resort to manual shutter increase customization , this is included in the photography program of the supporting firms.
• Overexposed image: The final output image will burn out and lose focus , to not want the image to be overexposed, we reduce the time to open the shutter but the image will not be beautiful and smooth, but if we want a nice smooth image, we open it. If the shutter is longer, the image will burn out?

The solution at this point is to use a light reduction or ND Filter (Neutral Density Filters).

Take photos with flash in daylight

Do you want to use the flash during the day? This technique certainly produces eye-catching results, but it also requires a very low exposure. Therefore, you need to use an ND filter to adjust the light received from the shutter, thereby giving the desired shooting results.

How does ND Filter work?

An ND filter is actually a piece of dark glass (or plastic) designed to change the amount of light that passes through it, thereby changing the amount of light hitting the camera’s sensor without affecting other factors like The color of the light or the polarization of the light is affected.

This allows camera users to use creative effects such as using wider apertures (for depth of field) or longer shutter speeds (for time-based effects). ..

Types of ND Filter

Sort by shape

Round ND filter

Advantages: Lighter, easier to store than square type and cheaper.

Weakness:

• Fits only lenses with the same thread size, can be used to step down to a different diameter for smaller lenses, but there is a chance of darkening in four corners.
• The assembly is slow, so you may miss a beautiful moment.
• Difficult to install other filters such as GND and difficult operation.
• Cannot be used with some convex lenses and ultra-wide or larger diameter lenses.

Square ND glass (rectangle)

The good: Square ND glasses are made to make the system faster and more convenient, can be mounted on a variety of lenses via a holder, and are very convenient when changing lenses are needed. filter and use in conjunction with the GND filter.

Cons :

• The cost is usually higher than the round type (but if used for many lenses, the cost of square ND can be cheaper than round ND).
• Bulky and harder to maintain.
• Sort by degree of light reduction

Classification by type of light reduction

• The 3-stop filter will let you go from a shutter speed of 1/250 – 1/30 of a second.
• The 6-stop filter will let you go from a shutter speed of 1/250 – 1/4 second.
• The 10-stop filter will let you go from 1/250 – 4s shutter speed.

When to use ND Filter

ND filters should be used in landscape photography , especially when you want to capture a lot of movement in the frame that creates movement in the image such as object movements, drifting clouds, human manipulation, etc. leaf vibrations…

How to choose the most accurate ND Filter

Determine the size and shape of the ND . filter

The size and shape of the ND filter depends on the lens, or the lens system where the filter will be installed. It is advisable to choose the filter style and size in accordance with the needs of use, the ability to operate (the level of convenience, the ability and speed to install the ND filter on the lens) and in accordance with the financial ability.

In addition, for convex lenses such as fisheye, super wide, and ultra wide, it is not possible to install round ND types , it is necessary to determine the square ND size suitable for use.

Determine the need to reduce light

The need to reduce light depends on the subject and content to be expressed in the photo. In which, the elements of art and conveyed content include clearly showing, blurring the subject, fast and slow motion, deformed shapes for moving, etc., thereby determining the required shutter speed to perform. presently.

Refer to the shutter speed for interpretation in the following table:

Notes when choosing to buy ND Filter filters

First, you need to pay attention to the thickness of the ND filter . On wide-angle lenses, a thick ND filter can cover the corners of the frame. So to avoid serious blur, look for a thin ND filter.

In addition, you need to be aware of the quality of the filter because buying a cheaper ND filter will certainly save money, but their durability will not last long and bring results not as expected.

Finally, don’t confuse an ND filter with a circular polarizing filter . Polarizing filters are used to cut reflections by filtering light rays along an axis. They also reduce the amount of light, but this is not their main function.

Above is information about the ND Filter filter that Tnhelearning.edu.vn shares with you. If you have any questions, please leave a comment below the article.