Ever since the camera was invented, we have always tried to copy one of the greatest wonders of nature: the human eye. Unfortunately, although well over a hundred years have passed since man “caught the light”, we are still far from surpassing, or even equal, Mother Nature’s work.
Try to think of the last wonderful sunset you saw at the beach: you will certainly remember the light and warm tones, the wonderful coloured reflections of the clouds on the sea and the golden sand. I am also certain you were disappointed when you tried to take a photo of that moment.
Whether you took it with your mobile phone or with your beloved reflex camera, it doesn’t matter: if you have correctly exposed the sky, the beach has become a silhouette and if you have correctly exposed the beach, the sunset will be pale and washed out or worse, completely white (often described as “blown out” or “highlights clipping”)
Why? Because in the visible spectrum, your eye sees much better than your camera.
What is Dynamic Range?
Dynamic Range defines the difference between the minimum and maximum brightness value that an image sensor can record. In essence, the Dynamic Range indicates the ability of your camera (and your eye) to see details simultaneously in very light and very dark areas of the scene. Spoiler: our eyed have a much higher dynamic range than our camera.
How much? Almost double!
This explains why, when observing a bright sunset, we can see details throughout the scene. Whether in the heavily lit sky, on the beach or on the ground in front of us, we see everything, yet our camera cannot. Furthermore, the human eye is able to grasp fragments with different exposure in different areas and the brain pieces this all together to give us the final image.
The unit of measurement of the Dynamic Range is Exposure Value (EV) and at the time of writing this article, an excellent DSLR/Mirrorless has a Dynamic Range of about 13-14. We could go into the technical detail of how the photon interacts on our sensor, but in addition to boring you to death it would not particularly help your next photoshoot.
How to take better landscape photographs
If even the best camera has a Dynamic Range that is half that of the human eye, how can we hope to be able to capture a beautiful sunset or sunrise? There are several methods to overcome the problem which we can group into two big groups:
- Advanced post-production techniques (HDR, Manual Blending, Multiexposure, etc)
- Use of GND filters
Which of the two is better? Does one exclude the other? Overall, applying the second solution, photographic filters, is preferable for several reasons including:
- They allow us to have a clean in-camera shot which guarantees better final quality.
- If the shot isn’t right “in-camera”, you can try again straight away without waiting to post-process.
- There are filters that cannot be easily replicated in post-production. A combination of ND, GND and Polariser is impossible to exactly replicate.
- Long exposure needs time and you captures movement, the two things together means you probably have one chance and blending is almost impossible with movements. Read our guide to long exposure here.
The second does not exclude the first! On the contrary, having a starting shot with higher Dynamic Range allows you to work better in post-production. In extreme cases, it is possible to use a GND filter and then apply digital blending or advanced HDR to further expand the light/shadow range.
NiSi Neutral Density Graduated Filters
NiSi manufacturers high quality graduated neutral density filters (GND) with which you can overcome the limits of the dynamic range of your camera, simultaneously capturing details in the light and dark areas of the scene.
The GND filters are used in dedicated holders, such as NiSi V6. They have a darker part, at the top, and a central transition that fades towards total transparency. This transition can be more or less smooth and differentiates according to the various types of GND: Soft, Medium, Hard and Reverse.
The transition must be positioned where you see the greatest difference between light and shadow. In this way, the GND filter will help balance the image. There are several available densities that enable you to gain dynamic range. The most common strengths are 2, 3 and 4 stop, but some filters (like the Soft) are also available with 5 stop density. Using the popular 100x150mm 3 Stop GND Medium Filter for example, your sensor will capture information even at 16 EV (assuming a maximum dynamic range of 13 EV of the sensor). This is because the information available in the extra 3 EVs is compressed by the GND filter, therefore they become readable by the sensor.
Graduated neutral density filters are available in the sizes of 75mm, 100mm, 150mm and 180mm. The NiSi V6 is the perfect holder for 100x150mm GNDs, while the 150mm filter holder (or the NiSi S5 with polariser included) is what you are looking for for your Nikon 14-24, Tamron 15-30 and other wide angle lenses without a threaded front.