While you can absolutely create compelling portrait photos using just a single light, moving into using multi-light setups opens a lot of creative and technical options that simply would not be possible otherwise. One of the most useful of these is the hair light, and this great video tutorial will show you how to place one properly to get the best results.
Coming to you from Daniel Norton Photographer, this excellent video tutorial will show you how to properly place a hair light for a portrait shot. The reason a hair light is so useful is that it can help to separate your subject from the background. When you use a background that is similar in color and/or tone to your subject's hair, the two can start to blend, and it can be difficult to tell where one ends and the other begins. A hair light remedies this by aiming a second light at your subject from behind, creating a halo or rim that distinguishes them from the background. The effect is often subtle, but it makes a major difference in the final image. Check out the video above for the full rundown from Norton.
If you would like to continue learning about how to light a portrait, be sure to check out "Illuminating The Face: Lighting for Headshots and Portraits With Peter Hurley, which is currently on sale along with the rest of the Fstoppers store!"
