Traditionally speaking shooting into the source of light is not regarded as good photographic technique. I have a good friend who is highly talented and has a body of work I admire greatly. She has shown consistently how effective this technique can be used. Several of her portraits have moderately to heavily backlit subjects and every time I see them I nod my head slowly in agreement.
I think the thing that most people are trying to avoid when a subject is backlit is the lower contrast and the potential for flare. Plus, unless you have a camera with decent dynamic range you will completely lose out on exposing the side of the subject facing the camera. Much of this can recovered with software in post production, but you need to have something there to work with before you begin. Another potential drawback is the chance for flare. Me, I don’t mind these ‘flaws’ in my photos, in fact, I like the character it adds to a photo. And like everything else in life it needs to be done in moderation for it to be effective.
So, the next time you think you can’t get the shot because you are not positioned correctly with your subject and light source, go ahead and shoot. Give it a try you never know what you’ll come up with.