Mastering fog, once and for all
QUESTION
“In your last article about working with bad light, you mentioned fog rising off the lake. I love the moody look of fog, but it seems to be a disaster to try and photograph wildlife in. Do you have any suggestions?” - David Hobbes, Illinois.
Yes. Yes, I do.
Fog, that beautifully ephemeral atmospheric condition that inspires awe and wonder while simultaneously driving wildlife photographers insane the world over. If you have spent much time in the field toting around a telephoto lens, chances are you have encountered foggy situations in which animals appear to materialize out of the aether. And if that’s the case, you have likely found yourself frustrated with trying to figure out what to do with those photographs once you brought them home.
Before I dive into working in fog, it’s important to get a few basic facts out of the way here. Understanding how fog works and how it’s created can mean the difference between deleting a morning’s worth of images and creating some of the most breathtaking photos of your life.
Fog is what we call a cloud that forms within 50 feet from the ground. Clouds are called clouds when they form above 50 feet. There is technically no physical difference between fog an clouds. It’s just a matter of how close it is to the ground.
Probably the most important thing for any photographer to understand about these ground hugging clouds is that there are two types of fog: radiation and advection fog
The difference is critical because one holds the potential for something truly magical while the other is often little more than a lesson in frustration.
Radiation fog is the most common type of fog across continents and is what happens when the air rapidly begins to cool near the ground and hits its saturation point. This is what’s often referred to as ground fog. In the morning, when things begin to warm up, radiation fog begins to “burn off.”
Advection fog is different. Advection fog forms when warm moist air moves over cold or cooler surfaces. When this occurs, the warmer air is quickly cooled by the ground (or water), causing it to drop in temperature and reach its saturation point. The fog that comes rolling in off the ocean in places like San Francisco or the infamous London fog are both examples of advection fog.
Radiation fog happens under clear skies. Clouds in the sky slow down the loss of heat and therefore keep radiation fog from forming. With clear skies, heat dissipates quickly, especially in the fall, allowing for radiation fog to form.
Because advection fog forms from warm air moving over cooler ground, it often forms under overcast skies whereas radiation fog does not. And this is important to understand.
Still with me?
The difference matters because it means that with radiation fog you will eventually get sunlight piercing through, whereas with advection fog you may not.
One of the big challenges of nature photography is coming to terms with the fact that our emotional experience of a situation can be difficult to record in a two-dimensional medium. Something speaks to us, moves us, brings us to tears, or electrifies the senses. But try as we may to convey that experience with our photography, we often fall far short.
This is often the case when trying to create something beautiful in the fog. We are moved by what we see, captivated by the ethereal quality of what materializes before us. But try as we may, our images often fall far short of what we saw and experienced.
But the challenge of fog, if we are able to work past that emotional experience of it all, boils down to only one thing: contrast.
Fog obliterates contrast. It devours all semblance of highlights and shadows, those things that create depth, dimension, and detail. Because fog is composed of physical particles of water suspended in the air that you are attempting to “shoot through,” it also challenges our autofocus systems while muting and muddying colors.
Contrast is all about light juxtaposed next to its absence. And since fog devours light, it devours shadows and therefore contrast as well.
This is the challenge of fog.
In order to create compelling images that capture that moody and ethereal quality we experience with fog, we must find ways to bring contrast into our photographs.
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Sometimes the fog is so all encompassing, so enveloping, that there is nothing but fog and maybe a dim animal shaped object before you. Welcome to advection fog photography. When working in advection fog under cloudy skies, you can abandon any hope of finding contrast naturally. This is the most challenging of all situations and success or failure usually depends upon your ability to bring out contrast in the subject through post-processing (think: high-key black and white).
But radiation fog is different; above that ground hugging layer of cloud are clear skies and the sun’s rays beaming down.
When we find ourselves photographing wildlife in radiation fog, such as one might encounter during the elk rut right now in the Smoky Mountains, if we slow down and observe our surroundings, we can often find that the sun is still impacting the situation on some level. It might be small, but it’s usually there to some degree. And as the air warms, the fog eventually “burns away.”
Working with radiation fog means that we need only find the direction of the sun to begin piecing together compositions.
Now, in radiation fog, if the sun is behind us, then it is bathing both animal and fog evenly. This means no contrast. Light is bouncing back at your lens off all those water droplets helping to diffuse what little light and contrast that could be found otherwise. But if we move ourselves so that the subject is hit by light from other angles, suddenly the physical mass of our animal begins to create shadows. And it’s those shadows that create the contrast needed to work in the fog.
Personally, when working in radiation fog, I prefer to position myself with the sun directly behind whatever animal I am photographing. This creates the maximum amount of contrast possible. As the sun slowly becomes brighter, as the fog begins to wane, the shape and then eventually the silhouette, becomes more and more pronounced.
With the image of the bear in the fog above, the dark background you see here was created from the shadowed side of the mountain that the sun was cresting over. Working with a treeline or a mountain that is in shadow like this, allows for the wafts of fog to become pronounced as the light pours through the water particles. It’s sort of like working with falling snow in that the darker the background is, the more pronounced the falling snow becomes. In composing with a dark background like this, the fog itself takes on a physical quality in our photograph, allowing for infinite possibilities.
Understanding the need for contrast like this allows us to turn fog into an ethereal and beautiful element of our composition. Understanding what type of fog we are in, allows us to consider those compositions beforehand.
This is where art and science become one.
So, let’s simplify all this. . .
ACTIONS
Knowing the difference between radiation and advection fog is important. A simple glance at your weather app will tell you if it’s going to be sunny or cloudy. If sunny, then you know it’s radiation fog and eventually you will have some truly incredible light to work with. Working in fog is all about finding contrast. Knowing this means you can spend that time when there is no contrast to move into position and set yourself up to work with the light as it begins to cut through the fog.
In essence, working with fog is similar to working with silhouettes.
If you want to learn more about working with silhouettes, and therefore fog, check out the Summer 2023 issue of PhotoWILD Magazine where you will find an in-depth discussion on Mastering Silhouettes.