Whenever there is sky in the frame it is so easy to let the camera meter fool the photographer.
The camera meter reads the entire scene and comes up with an average exposure. But when there is bright sky (or bright snow or a bright beach) it throws off the average and makes the scene too dark.
In this photo at San Francisco Botanical Garden, I really wanted a bright airy look to show off the reddish foliage of the Lorapetalum.
The meter does not know I want a light airy feeling and, thinking it is an average tone, overcompensates for the sky, making a dark moody shot.
Before and After Slider
It was an early misty morning so opening up the exposure, technically overexposing the photo by about 1.5 stops, gave me the bright look I wanted.
Using the Light is Lesson 3 in my award winning garden photography workshop ebook Think Like a Gardener.