Getting to Know Graduated ND Filters – Soft vs Hard-Edge

If you’re a landscape photographer, a graduated ND filter is either your best friend, or the best friend you haven’t met yet. Landscape photographers are a committed bunch who set up tripods in the cold winter sand well before the sun breaches the horizon, who trek to a mountain’s summit to capture a sunset. But without the right tools, landscape photographers’ commitment can go unrewarded – the brightness of the sunrise or sunset bleaching the image with highlights. An opportunity lost.

Traditional landscape photography is all about getting the image right in camera, with as much dynamic range as possible and without the need for excessive post-production editing. Photoshopping or editing to suit your aesthetic can always be performed post-photograph, but not if you don’t have the dynamic range to begin with.

All cameras have limitations, but you can retain incredible depth and detail in the shadows and highlights by using a graduated ND filter. Reducing the highlights of an overly bright scene by using a graduated ND filter will not only make your images pop but also allow you the best post-production capabilities.

Let’s learn more about these filters and what they can do.

There are two main types of graduated ND filters with one major difference – the edge. On a graduated ND filter, the edge refers to the blend. If you look at the gradients below, you will notice how they blend differently from dark to light.

A soft-edge filter provides a gradual fade from dark to clear glass. Oppositely, a hard-edge filter has quite a definitive line and a sharp blend between dark and clear glass.

Graduated ND filters come in varying strengths to accommodate different lighting situations, typically anywhere between one and three f-stops of light. For example, if a sunrise is particularly harsh, you may need a stronger filter (darker gradient) to cut the light and balance the exposure with the foreground.

Graduated ND filters also come in different fading patterns for more specific light conditions. Aside from the most common even split between light and dark glass, you could tackle that same harsh sunrise with a centre graduated filter. Urth’s Centre Graduated ND8 Square Filter Plus+ reduces 3 f-stops of light across the centre of the filter. This allows you to reduce the glare and flare of the sun across the horizon while retaining the details in the foreground and skyline, leading to a more evenly balanced exposure.

Because of the definitive hard edge of a hard graduated ND filter, it is best used in landscape photography when there is a naturally occurring hard edge in the landscape i.e. a horizon. If you’re shooting a sunrise over the ocean, you can position the hard edge of your graduated ND filter with the horizon to reduce the highlights in the sky and balance them with the lowlights in the other half of your scene.

A soft graduated ND filter, much like its name suggests, is best used in softer lighting situations when you want improved dynamic range. A soft-edge filter may be useful in circumstances when there is no definitive line like a horizon in your scene.

These filters are perfect for naturally blending highlights and lowlights for more depth and detail. Imagine shooting in a forest, for example, with the sun piercing the canopy. A soft-edge filter will help you regain the lost highlights in the sky above the trees while slowly fading towards the forest floor.

Graduated ND filters come in various shapes and forms. For ease and universality, Urth offers circular graduated filter options that thread onto your lens much like all of the filters in our range.

To mount our graduated filters, you need to first find your filter size. Check the markings on the front of your lens and you should find a number most likely within 37mm and 95mm. Be careful not to confuse this number with the other markings on your lens that denote the focal length! Now, place the filter flat and screw clockwise, being mindful of over-tightening.

Once your graduated ND filter is securely fastened to the front of your lens, you can start experimenting by rotating the filter to align the darker part of the glass to cover the brighter part of the landscape or scene before you.

Urth also offers a range of square graduated ND filters that can be mounted on any lens with our Square Filter Holder. They’re ideal for those with a large collection of lenses, or those wanting more control choosing the edge placement within the frame.

It’s pretty common to have more than one graduated filter in your kit because of the various strengths available. If you’re new to this world, it’s best to choose an average strength, reducing up to 2 f-stops of light. Once you’re experienced and have a greater understanding of when and where you plan on using a graduated filter, you can increase the strength of light reduction.

It’s important to note that as a general rule of thumb, you should aim to keep the sky and foreground within one f-stop of each other. This will help you when it comes to determining the appropriate exposure values.

Investing in quality graduated glass is one thing, but the real investment is your time. To take stunning landscape photographs, it’s a combination of having the ideas and the right gear. The only way to realise your ideas is to pursue them, to practice and then make perfect.