Getting the right exposure can be a problem for landscape photographers. The sky is often equally important as other elements in the composition, but exposing for the sky while keeping everything else sufficiently bright can be a challenge.
The image below is very complex, with lots of different elements in the composition. I spotted the interesting clouds moving in, so I positioned myself in a way that I could capture the sky and other important components, such as the rocks and the trees in the middle of the image.
As you can imagine, getting the correct exposure for this picture was not easy. The two images below illustrate the point. The first one was exposed to keep the detail in the sky, and as you can see, the foreground has gone very dark.
The rocks in the foreground of the image form an important aspect of the composition, therefore I wanted these to be nicely exposed. However, exposing for the rocks led to the detail in the sky being lost.
I usually use the Zone System of exposure. The Zone System was created by Ansel Adams and Fred Archer in the 1940s. Their idea was to create a system that allows for an image to be visualised in the mind before the shot is taken, controlling the exposure so that the image turns out as planned.
Although I use the ‘full’ concept of the Zone System for most of my shots, I have created a very simple interpretation of it. I find this simple trick works about 80% of the time, and it certainly worked for the shot of the castle.
My simplified system involves the following. I look for trees or other similar coloured vegetation, particularly in the middle area of the shot, and I take a light meter reading from that area.
From that exposure, I underexpose the shot by one or two stops. For example, the trees in the middle of the shot gave me a reading of 1/60 second at f8. Instead of using that meter reading, I exposed the image two stops below, which in the case of the castle shot, was 1/15 second at f8.
This method results in slight underexpose in the trees in the middle of the frame, but there is still enough detail that can be seen. The underexposure provides just about the right level of brightness in the rocks in the foreground, and it results in the sky having the right amount of detail.
Understanding how light and meters work is fundamentally important to photographers, particularly landscape photographers. Light is reflected off every part of a scene; trees, water, rocks, people, roads etc. The light meter ‘reads’ these reflected values and then averages them out as ‘middle grey’, or in light meter terms, 18% grey. The meter then provides an exposure guide, which aims to bring the scene into the middle grey zone, which is why the sky can very often be burned out. However, by taking something that reflects middle grey (the trees in the middle of my shot) and underexposing them by one or two stops, the whole exposure of the image is pushed towards the darker end of the zone spectrum.
Using this technique results in images that require very little tweaking in post-production. Any alternations that I do make in post are mostly to deepen the sky and bring back the detail in the trees.
This little trick is really useful when exposing a tricky scene.