Sunday, January 19, 2014

Photographing Snow

Its winter time here in Boise which means a good amount of snow.  Snow can be one of the hardest conditions to photograph in.  There is a lot of light with snow so you'll need to have an understanding of F-stops and shutter speeds.

Here is a quick exposure lesson.  F-stops are how large the "eye" of the lens is open.  And the shutter speed is how fast the light is allowed in the lens.

F-stops tend to start with 22 and go through 2.4 or 1.5 (but not all lenses go that high or low).  How these numbers came to being wont help you understand which number to use while in the field.  What will help though is understanding the point of those numbers.  The larger the number the smaller the pupil of the lens is, the smaller the number the larger the pupil of the lens is.  When a camera is set to f22 the pupil is restricted, allowing a small amount of light in.  On the other end at the f1.5 the pupil is fully open, allowing an unlimited amount of light in.  Using my "eye" example, your pupils close to an f22 when you step out into the sun and open to an f1.5 when you walk into a dark room.

Then there is shutter speed, which I think of like a curtain.  When a curtain is shut the light isn't allowed into the room (we are imagining a black out curtain).  What this does for the camera is stop motion, when that number is larger the shutter closes faster and a smaller number indicates it closing slower.  An example of this is when photographing a river, want the river to be blurred just set the shutter speed to 60, want the river to be crisp set the shutter speed to 500. (The numbers for each camera are different, please do not quote my numbers)

Now that I've given a longer than planned lesson on f-stops and shutter speeds we can talk about snow.  One of the best things to do is take as many photos as you can and write down what you did.  The way I go about photographing snow is understanding the situation.  Example the photo right below this was taken under a large tree.  I knew there wasn't as much light and I was shooting into the dark branches.  So I knew to use a mid range shutter speed, and an f-stop of 10.  

For the photos above I needed to use a larger shutter speed and an f-stop of 18 to 22 because there is a lot of foreground and sky.  The snow reflects light to the lens along with the overall brightness of the day.