Recently I was showing some of my current favorite pictures to a friend who has 50 years' experience in the field, both as a photographer and teacher. She picked up the prints and looked at them with a poker face, giving me no hint as to her judgement. Then she lay them down one by one, as if she were showing a Las Vegas dealer her royal flush and said, "Backlighting, backlighting, backlighting, backlighting, backlighting!"
Although I was certainly aware of the advantages backlighting can lend a photograph, I hadn't noticed that my favorites this time were all backlit. Soon afterward, I set out with my favorite model and tested some frontlighting and backlighting situations.
Fiona was up on Oma's balcony where the evening sun shone right into her face and, as a bonus, light was kicking up from the yellow-and-white striped awning below her. It was as if I had a 20'x40' California Sunbounce right under her chin! The combination fills her eyes with light and creates a pleasant golden patina on her skin.
Then we went out front and she rode her roller back and forth - first into the light...
...and then away from the setting sun. As could be expected, she had to squint her eyes a bit when facing the bright sun. On the other hand, there is a nice catch-light in her eyes, making them look alive. The golden tint of the sun can be seen on her skin and on the foliage behind her. Her hair nearly blends in with the background in some places.
With backlighting her hair stands out clearly from the background and there are no harsh shadows on her face. There was still enough ambient light to make her face clearly visible. If that hadn't been the case, I'd have had to work with a flash set-up. In contrast to the photo below, the one above has her positioned almost directly between the sun and me. In the picture below, the sun crept onto part of her face. If you don't meter for such highlights, the details get lost in the bright areas and there is nothing you can do to get them back.
Backlighting is an advantageous lighting situation for your models. In the studio, a "kick light" is directed at the back of the subject, usually to highlight the hair and separate the model from the background. In outdoor situations that is not always possible, but by having your subject between yourself and the light and carefully metering for the highlights, you can capture some of that studio feeling in your photos. Backlighting is so popular in glamor photography that it is often coupled with decreased clarity (a slight blur) and brightened corners to add that dreamy look to the picture, as in the photo below.
Sometimes backlighting makes the picture what it is; without it, there would be less to enjoy!