Fog and frost can transform a routine scene into a moody, or even mysterious photo opportunity. While exceedingly beautiful, these conditions don't occur all that often, making them even more exciting to capture through your lens. Despite this, there are some outdoor photographers who avoid shooting in weather such as this. They argue that landscapes are best captured on a clear day with great visibility. Yet, to truly succeed in outdoor photography, we must learn to take any situation and work with it to the best of our ability. As the artist Jewel sang, "Nature has a funny way of breaking what does not bend."
To better predict when fog and frost will appear, it helps to understand how they develop. Don't worry, it's just a refresher, and you won't be tested at the end. Frost forms as a result of water vapor that has condensed over a large surface area. A thin layer of liquid water now covers the object. When the temperature is cold enough to crystallize the liquid water, frost will form.
Essentially fog is a cloud that forms close to the surface of the Earth. In order for fog to form, relative humidity must be at or very close to 100%. When the air is nearly saturated with water vapor there is a large supply of moisture for fog to occur. The source of water vapor for fog is often a body of water like a lake or an ocean. Interestingly fog can also form over a field of grass as a result of a special type of evaporation called transpiration. Transpiration occurs when dew from the leaf of a plant evaporates off the surface of the leaf. As such, a large grassy field can supply ample water vapor for fog to form over the location.
Chances are, your autofocus system is no match for a dense layer of fog. Even a sophisticated DSLR will struggle to lock onto a subject successfully. The trick is to switch to manual focus and trust your eyesight to focus. If the thought of this makes you cringe, or you're an eyeglass wearer, there are new features to make this much easier than it used to be. Perhaps the best option is "focus peaking", now available on many consumer model cameras. To use it, slowly twist the manual focus ring while looking at the subject in your LCD screen. Once focus is achieved, the subject will appear to be outlined in a bright color.
Both of these conditions are notoriously tricky for the camera's internal meter to handle properly. If you simply photograph them in automatic mode, they will end up with more grey than desired. This results in a flat scene that sorely lacks in any real sense of depth. The solution is to add one or two stops of exposure by adjusting your camera settings or using exposure compensation. This will help to brighten up a dull landscape while adding much needed contrast.
With these simple workarounds, it's possible to take an otherwise ordinary moment, and turn it into a special work of art. Keep an eye on the weather report and head out with your camera when they are likely to occur. In my experience, the early morning is your best bet. Of course there are those occasions that surprise even the most prepared meteorologists. When this happens, use your camera phone or pocket sized point and shoot to make a photo. I keep a mirrorless camera with me at all times as it's small enough to travel well, and offers full manual control.
These elements can also have a dramatic effect on man-made structures. Even the mighty Empire State Building in New York City can't rise above a thick veil of fog. While the main subject of this image is clearly a cityscape, it also reveals the true power of nature. If you've never tried to capture these conditions with your camera, now is the time to start. As you become more accustomed to shooting in all kinds of weather, you'll likely come to prefer scenes that are aided by fog and frost.