Imagine you are on the beach. You and a friend are having a great time, so much so that you want to take a photo to capture the moment.
You get your friend to stand by the water. You vary carefully stand your friend with his back to the sun as you correctly have judged that having the sun behind YOU will cause your friend to squint because HE will be looking into it.
Posed and ready, you take the photo. Luckily, your friend does the same for you (it just goes to show what a great time you are having).
You look at the resulting images. They are poor.
Neither of you are squinting, or at least, you dont think so. But unfortunately the eyes and face are in deep shadow and none of the features are visible.
The reason for this is that the bright background has fooled the camera into underexposing for the face. The background is perfectly exposed but the face isnt.
The trouble is, if you compensate the exposure and expose for the face, you will find the background is overexposed and losing detail of that lovely beach, sea and sky.
There are two possible remedies. First, you could move your friend (and he move you) so that the sun is not behind him or you but to one side. If the sun is in front of your friend and over to one side or the other then you will get light on his face.
The second option is to use fill-in flash. Most cameras will allow fill flash to be used. This will allow the background to be perfectly exposed and the flash will illuminate the subject in the foreground.
Move the subject or use flash
Eric Hartwell runs the photography resource site http://www.theshutter.co.uk and the associated discussion forums as well as the regular weblog at http://thephotographysite.blogspot.com
