What Is A Graduated Neutral Density Filter?

What Is A Graduated Neutral Density Filter? - Mastin Labs

If you've ever felt frustrated by blown out skies in an otherwise perfect image, a graduated neutral density filter may just be your new best friend.

Sometimes referred to as a graduated ND filter, split neutral-density filter, or just a graduated filter, these simple tools can save your sky detail and help bring your entire image into a dynamic range.

Here, we cover what they are, ways to use them, and even how to replicate them in the digital darkroom, using Lightroom as an example.

What is a Neutral Density Filter?

The most straightforward way to think about an ND filter is that they're kind of like sunglasses for your lens. And they do precisely what sunglasses do for your eyes—They block light.

In photography, these filters are often graded by how many stops of light they block. Adding this additional element of light control means that you have an even greater range of options in directing the outcome of the final image.

Most commonly used in landscape photography, ND filters are how photographers achieve effects such as silky looking streams of water or wispy clouds. The filters allow them to use a long exposure to blur the movement of the water or clouds without overexposing the photograph.

By Steve Halama

What is a Graduated Neutral Density Filter?

graduated ND filter does the exact same thing, but the effect graduates from it's full strength to none at all. See the example below for a visual explanation.

Replicating a Graduated ND Filter in Lightroom

It's super easy to replicate the effects and reap the benefits of a graduated ND filter in Lightroom. It doesn't completely replace the benefit of the physical filters, but as long as you shoot in RAW and don't blow out your highlights, it's a fantastic tool to bring back details in the sky.

  • Select the Graduated Filter tool in the Develop module and lower the exposure in the tool options.

  • From close to the top of the image, click and drag down towards the horizon line. Once in place, you can adjust the exposure, (or other settings) until content.
  • If you want to toggle on/off the red overlay, use the ‘O' key to do so.

You can also see Kirk use this technique in a live edit video.

Using GND Filters on Your Camera

In the age of the digital darkroom, the frequent need for a physical graduated ND filter may have diminished, but is not altogether gone. Even while shooting digital, these filters can be handy.

When shooting in RAW, you retain loads of information as long as there is detail data gathered. However, if you blow out the sky to absolute white, there is no detail to work with.

The highlighted red area indicates blown-out whites. This means that there is no data in that area.

If you find yourself in this situation, you could bracket your exposure over multiple shots and composite them together, but that's quite a lot of work, especially when you can so quickly get the shot perfect, in-camera, by simply using a graduated ND filter.

The filter will help to bring the sky and blown-out area into the dynamic range of the rest of the exposure. If you're shooting digital, what you get is a single RAW file with all of the highlight and shadow information you need.

Closing Thoughts

Especially for the portrait and wedding photographer, a graduated neutral density filter has a more immediate practical use, compared to a full ND filter. It is this graduation that allows you to essentially have two exposures in a single frame, keeping both your subject and the sky in detail.

Graduated ND filters come in many shapes, sizes, and price ranges, and some even have multiple stop increments within the same filter. None are better than the others, but each come with their own pros and cons.

Some screw to the front of your lens. They're almost unnoticeable, but you have to buy a separate one for each size lens, which can become quite costly.

Another option is to buy a filter mount system. This is hardware that attaches to the front of your lens. You then slide the filters into the hardware and in front of the lens. It's a bit more cost-savvy but very bulky. I will say, though, it does make you look like a badass.



A Lee hooded filter holder on a Canon

I absolutely recommend at least playing around with some. Aside from their practical use, ND filters are a lot of creative fun too!

Are there other ways that you like to use ND filters? Let us know in the comments below. Also, if you're not a member already, come join us on the Mastin Labs Facebook community! We would love to see you there!