How to use ND gradient filter in landscape photography?

Since the invention of the camera, we have been trying to record beautiful moments, but unfortunately, although the camera has been invented for more than 0/00 years, there is still a long way to go to record natural scenes in nature. Why? Because the visible spectrum seen by the human eye is much better than that seen by the camera.

Dynamic range

The parameters describing this function are called dynamic ranges. Basically, this is the difference between the minimum and maximum brightness values that can be captured by a device such as an eye or a camera sensor. In fact, the dynamic range determines the camera's ability to see details in very dark and very bright (bright) areas of the scene.

Shooting problem

This is why when you look at the beautiful sunset with your own eyes, you can see all the details of the scene (whether it is the sky or the ground). But when taking pictures, you will eventually encounter overexposure in the sky or underexposure on the ground. The dynamic range of the camera can only convey the details of one area, so it must be selected.

However, the dynamic range of even the best camera is only half that of the human eye. So, how can we hope to convey the beauty of sunset or sunrise in amazing details?

There are many ways to solve this problem, but it is recommended to use ND gradient filter.

What is a gradient ND filter?

ND gradient filter consists of two independent parts; For completely transparent parts, by adjusting the darker part of the filter to match the brightest part of the scene, the difference in exposure (dynamic range) in the frame can be reduced.

Reducing the exposure difference means reducing the dynamic range in the scene, so it allows your camera to capture the details of bright and dark areas at the same time. Basically, the filter works just like the sunglasses of a camera.

ND gradient filter type

Gradient ND filters usually have different transition types between the transparent area and the shadow area of the filter. Therefore, we can distinguish three groups of filters:

1. Filters with hard edges are characterized by clear boundaries between transparent areas and dark areas (obviously, one boundary ends at the other). Therefore, when the light and dark areas of the scene are clearly separated (such as the sea level), they can be used.

2. Filters and softened edges are characterized by smooth transition (from dark to bright, which is relatively gentle), so they are used when the transition between light and dark parts is unclear. A typical example is shooting in the mountains.

3. The inverse filter is nothing more than a hard-edged filter, and its dark area gradually darkens from the dividing line to the top of the filter (that is, its center is darker than the edge). Basically, they are designed to better cope with sunrise and sunset, and the light on the horizon (in the middle) is stronger. If you like this seascape, then this filter will always be your best "friend"!

Which ND gradient filter do you want to buy?

Another difference between filters is the material of construction. The highest quality filter is made of optical glass. But it is not a good idea to install cheap filters on hundreds (thousands) of lenses.

Finally, filters have different levels, or their ability to block light in the darkest areas is different. It's basically how dark they are. Usually in landscape photography, this difference depends on one to four steps during sunset or sunrise, depending on the weather. This is why these gradients are almost unique in the market.

How to use gradient ND filter when shooting

It is very simple to use ND gradient filter when shooting; Try to get exposure data in the darkest and brightest part of the scene (usually the sky). The difference in exposure will determine the intensity of the filter to be used, assuming that the sky data is 1/250 and the foreground rock is 1/30. The difference between these readings is three steps (250 >:

125 >60 >30), so a 0.9 filter (three steps) is needed to balance the exposure.

Now just connect the dark side of the filter to the bright side of the scene. This is why the scrolling filter is meaningless, and it will not be able to align the darker part of the filter with the scene like the nozzle filter.

In order to avoid holding the filter by hand (if it is combined with other filters, there may be problems), you can buy a special bracket, which can be installed in front of the lens to do this for you. There are many solutions on the market, but the best one is V5 of NiSi filter.

Professional holder. This is the only mounting base (16 mm wide on a full-frame camera) that can simultaneously mount three different filters and a polarizer without vignetting.