I had a new client call at the beginning of the week asking for some aerial photos of a project "as quickly as possible". Of course, I immediately asked if having a nice sunny day, that would produce beautiful, blue sky images, was important. You see, there are two things that I don't like about winter photo missions. The first, is the fact that 95% of everything below you is white. Very monochromatic. The second is that it's cold. The planes and helicopters have heaters, but I still have to stick my hands out of the aircraft to shoot images, and let's not forget about that cold blast that hits you in the face and immediately makes your eyes water so much that you can't see, much less compose, much of anything. But enough of my whining.
Shooting this "monochromatic landscape" from the air is more demanding for the simple fact that all of that white throws off the camera's metering. It tells your camera (because it is seeing mostly white) that everything is white. So that anything that isn't white (lets say it's your kids playing in the snow) is usually pushed much more towards the darker end of the spectrum, or basically, underexposed. So how to combat this? Here are a couple of simple things that you can do. First, shoot in RAW. As a non-compressed format, it will give you a couple more stops of latitude to work with in post processing. In other words, with the proper software, you will be able to pull some detail out of those underexposed elements of your images. The second thing you can do is to dial in your exposure compensation. When shooting scenes with lots of snow, you want to add a stop (+1) of exposure compensation. This will bring up the level of light that the camera records (1 stop) so that anything darker than the snow (which is basically everything on a sunny day) will be a stop lighter, and will allow for more detail to be brought out from the darker areas. The drawback to this, is that all of your bright white areas (i.e. the snow) will be brighter, including a higher percentage of overexposed, or "blown out" areas in your image. If an area is truly blown out, then there is no information (detail) left in that area- nothing to try and "bring back" in post.
So how do we successfully capture a snowy day, bright sunshine, image, and retain detail and information in both the snow and the darker areas of the image? It's a balancing act, really. If you start with what your camera's meter is telling you to be the proper exposure, dial in a +1 exposure compensation, and make sure you're shooting in RAW, you should be close. In fact, from this point, you should be able to import to Lightroom 5, Adobe's latest version with the "highlights" and "shadows" sliders, and work those sliders to bring up more detail in both highlights (the snow) and shadows (everything else). This type of shot will challenge your cameras ability to capture the dynamic range of the image. A less expensive, or older camera, with a smaller sensor, will not capture the same amount of dynamic range as something newer with a full frame sensor, so your results using this method will depend on what you're shooting with. And remember, pushing those Lightroom 5 sliders too far will end up giving you an overdone HDR (high dynamic range) looking shot, so use them wisely. This type of shot is going to be a compromise most of the time. Concentrate, and expose for, the areas of the image (your kids playing) that really matter. After all, you probably don't want to see every detail in the snow, do you?