I'm a former photographer so it's hard not to chime in.
If you look at SI swimsuit pics - they have lots of light on the subject and the background is dimly lit (ie: a sunset). Why? This is called a 'kicker'. The light from you KICKS you from the background.
Eg:
http://ecx.images-amazon.com/images/I/510TAp3KCFL._SS400_.jpg
Notice how the subject is very well lit, kicking her from the background which is secondary to the eye.
Yeah I know i'm a dick.
r