I often use light from behind to act as rim light in my studio portraits, and might even call that light hair light if it lights the hair. But that is not entirely correct, I think. “Real” hair light should be focused on the hair more, from higher up.
This portrait, or headshot, I took of a woman wanting a good profile picture for her CV and online services such as LinkedIn is a good example of how a hair light can make the ordinary lighting look a little bit more glamourous.
Lighting diagram for hair light portrait
The lighting itself is nothing special, I use this variant of a clam shell setup all the time for studio portrait, for the simple reason that it works very well. Here is another portrait of a blonde with rim lights from left and right, but no hair light.
Main light is a large 5-foot softbox Octa with a Profoto D1 250 Air inside, I always use that light modifier without the outer diffuser for a good combination of big soft light and a little more contrast than normal.
Simple DIY reflector for fill and catchlights
Under the Octa I placed a white sheet of foamcore on an arm, just to add a little fill from below. But, using white instead of silver, just gave me the fill, but no bright catchlights in her eyes. I like catchlights, but sometimes a large silver reflector can flatten the light and contrast in the portrait too much. That’s why I tried with a white reflector. But without the sparkle in her eyes, something was missing.
The simple solution was to put a small sheet of silver coloured metal on the white reflector for a good combination of soft fill and something that could add catchlights with its reflections.
If I would have only done headshots in this session, I think I would have brought the reflector closer to her face for more precise control, but she also wanted half-length portraits. That is why the reflector is so far away.
Modify your reflector for more control
Placing the reflector in this kind of clam shell-ish setups can be tricky sometimes, some say that the lower catchlight should not be visible inside the pupil, just on the iris, but that is a matter of taste.
Personally, I think it depends on the picture, sometimes it works, and sometimes it looks awful. But getting it to reflect in the right place can also mean that the other parts of a face recieves too much reflections, like with a large silver reflector.
Sometimes I experiment with placing the reflector close and cover some parts of it with black fabric. That way I can get fill and catchlights, but also add more contrast under the chin, for example. If it is a guy and he wears a white shirt, there is not much you can do as the shirt will often reflect light in under the chin.
The hair light
And finally, as this is a two-light setup, I guess I must write a line or two about light number two, the hair light. It comes from behind the model, high up camera right, and is a Profoto D1 as well, but with a gridded Zoom reflector.
The grid is a standard 20 degrees grid, and it narrows the light beam so it only lights the hair from behind and above. Some of the light spills onto her shoulder, but I think that looks good. It separates her a bit more from the background.
For people with medium blonde or darker hair, getting the lighting right is not much of a problem, but for really blonde hair, blowing out the highlights and removing all details is easily done as this angle bounces the light so it almost can look like an aura. But, just lower the light output and it will be fine, or add a ND-filter.
I should use this kind of hair light more, I think it looks good even if it feels a tiny bit like classic American portraits of stars from the eighties. But without the crazy backgrounds they liked to use back then.