Fill Flash + Catchlights

these catchlights are effective because although the picture has
a good tonal range, the eyes are very dark. The catchlights add
contrast to the image and draws our attentioni to his face. 

The catchlights are effective but in a different way. In this case,
the eyes are not dark but are located in a sombre part of the picture.
Like the other image, the catchlights bring out the eyes of the subject.

This fill flash is very effective in bringing out the tones of the
women's clothes in comparisson to the background. although the
subject is close to the wall, there isn't too much light spill and the
background remains slightly underexposed. 

I found this fill flash interesting because it doesn't attempt to
create sepereation between the subject and the background.
Instead it compensates for the underexposure of the perosn
created by the sun in the background. In this case the flash is
used to give te scene a good overall exposure.