If every day were a bright cloudy day, the world would be yours for the picture taking. Ah - if only we controlled the weather, right? But since we haven't yet figured out how to cue the clouds, we have to look for "pockets" of good light to optimize our picture taking conditions. Enter your friend, open shade.
Just like it's cousin, the cloudy day, open shade creates conditions favorable to picture taking because it is an evenly-lit soft place. When taking photographs outdoors with all-natural light, your biggest obstacles are hard-cast shadows and extreme brights and darks.
So what is it? Open shade is the place where light and shade meet to create an evenly lit space that is just off of the bright light, but not in it. You find it by looking for the hard line at the edge of the light - and then place your subject TOTALLY IN THE SHADE, but FACING the light.
Think garages, doorways, porches, overhangs, and alleyways. Anywhere a nice solid shaded area comes smack up against a wall of light.
You would never know by looking at this picture that just in front of Chloe was the high noon Las Vegas summer sun! The ottoman that she is laying on is right up to the edge of a cabana opening where she is facing that bright light, but not actually in it. 1/2 a foot back towards the wall and it she would have fallen into the dark. 1/2 a foot forward and it would have been too bright for a good picture! But right at the edge of where the two meet is MAGIC!
What to watch out for -
A common mistake made by beginners and (surprisingly) even some seasoned momtographers is when looking for open shade they go right to that beautifully shady spot under the tree in the backyard. While this may seem like a great idea, unless your shade tree area is very dense, most trees create what is known as dappled light. You know when you look at someone and see cheetah-like spots all over them from the shadows created by light coming through the trees?
Look at the top picture! The baby's got spots! What looked like a nice shady area really wasn't one!
Now look at the spots on the ground all around the stroller - that should have been our first warning. Before you start snapping under the tree - inspect the ground - do you see any of the telltale spots? If not, then go for it. If so, then it's really not true open shade - it's more like broken shade!
Again, your safest bet is to look for true shade next to or under a real stucture. Find that line between light and dark - put your subject i n the shade facing the light and VOILA!