This "after" needed some TLC in Photoshop.
Have you looked out the window today? Gray skies abound, and snow is on the way to Central Ohio (and rain and sleet and muck). It won't be too long before Old Man Winter comes in and covers the ground with a blanket of snow! (Maybe in time for Christmas?) Many people want to stay inside when that happens, but there is a lot to see and shoot when the snow is around; your favorite path through the forest takes on a whole new life. However, frustration can take hold when you get back home and see all that wonderful, bright gray snow! Yes, the snow really was white (unless you were out taking pictures by the side of the road), but your camera didn't think so. Why?
The camera's light meter needs to read a whole lot of different levels of light. This leads to a lot of confusion and hard processing, so the computer engineers decided to simplify the process. The first thing they did was to only let the camera see in black and white; well, gray, really. The next thing they had to do was to find out how reflective the world is. After making lots and lots of readings, the average reflectivity is somewhere around 18%. Now, not all things reflect 18% of the light back to the camera; in fact, very few things actually do. Snow, for instance, reflects much more light back to the camera. This means that, even though the camera is pointed at something white, it wants to make it that same 18% gray its programmed to see. (For more discussion on the way a camera meters, see here.)
The "Before" levels dialog box of the above image.
To the right is the histogram of the image above before I processed it with Photoshop. The image definitely fooled the camera. You can see that there is no true black to the image, and no true white (outside of some specular highlights). Beyond that, the image was slightly underexposed. What could be done to save it?
If you are using a compact digital camera or a D-SLR on one of the more automatic modes, you need to find your exposure compensation (EC) button or menu, and become friends. The EC does what it sounds like, compensates for the exposure being different than what the camera thinks it should be. Normally, you will find that it will increase or decrease the exposure by 1/3-stop increments. For snow pictures, you will want to bring up the exposure by at least one stop, and maybe more than that if there is not much else in the image (like trees or mountains or feathers). The wonder of digital is that you can see the result right on the back of the camera, so take some shots and see what you get.
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