Not sure if you were aware, but snow is white. Our modern cameras, phones included, don’t seem to know that. Have you ever taken a picture in a winter wonderland scene and thought to yourself that the snow looks gray? You might live in a city and the snow is actually gray from the smog and the dirt on the streets. But if not, don’t worry, your eyes are not deceiving you. What is happening is that your camera is unknowingly underexposing the shot. There is a cheezy saying amongst photographers that goes something like, “the image isn’t made in the camera, it’s made 6-inches behind it” or more specifically in your brain. I know, right! But there is some truth to it in this instance.
The camera is just trying to capture an appropriate exposure with the available light, meaning not over exposed and not underexposed. The software writers preferred a Goldilocks Mama Bear approach when writing the code. When the camera receives all the “light” in the form of the white snow, it thinks it needs to underexpose the shot to make sure it’s right in the middle. A good visualization of this is with the histogram. Stick with me, I promise this will be a brief Nerd Session. The histogram is a graphical representation of the amount of “light” in a photo. When a modern camera, especially phones, decides on an exposure, it tries to make the histogram a nice big bell curve right in the middle that doesn’t touch either end. An underexposed shot, or too much black, would have a histogram with a large peak on the left. Whereas an overexposed picture, or too much white, would have a large peak on the right. I promise this will make more sense in the example upcoming. When the camera sees the snowy image full of white, it tries to push the histogram to the middle, but in reality it SHOULD be over to the right, after all the scene is almost entirely white. Below is a side by side comparison of a shot I took with my Google Pixel 2 (phone) camera at Crystal Mountain in Washington. On the left is the original shot, including the histogram, showing a nice middle of the road histogram. At first glance the photo doesn’t look terrible, but I believe this is because we are now used to gray snow in pictures. In the photo on the right, all I adjusted was the exposure (+0.7 stops). You can see immediately see that the image is brighter, and the snow is actually white! Take a look at the histogram, it has been forced over to the right indicating a primarily white image, which it is. Now looking back at the original image, you can really see the gray snow.
If you are wanting to correct this while shooting, it is simply a matter of sliding up the exposure/brightness bar on your phone, or increasing the exposure on your camera. If you already have photos that you want to fix, don’t worry, you don’t need Photoshop to do this, it can be fixed with most phone apps by sliding up the brightness/exposure bar in the edit tools. Be mindful not to slide it too far, or you will begin to “blow out” the white areas and lose details in the snow.
Pro tip: If increasing the exposure reduces the contrast too much, use the shadows and black sliders to get that pop you are looking for.
I have included a black and white comparison below to really highlight the difference, pun intended.
This concept equally applies to the opposite scenario, a scene full of dark objects will naturally force the camera to overexpose, and the same corrections can be made in the opposite manner. I really hope you found this post insightful, and it helps you to better capture your adventures in the snow this winter, and in years to come.
Do you have any photography related questions? Comment below and I will hope to get tot them in a upcoming post.