Warmup 65

A STOP is a unit equivalent to 1/2 the light of the previous setting. The you change the shutter speed from 1/4 of a second to 1/8 of a second, we say that you have changed the exposure by one stop. Pretty cool, right? Here's a little visual to help you get the idea:

1/2 - 1/4 - 1/8 - 1/15 - 1/30 -1/60 - 1/125 - 1/250

Each step is considered ONE STOP of light.

Look at the photo below. Try to guess the shutter speed that was used to create this photo.