A low key portrait is one where light levels are low in almost all of the image. Shadows and low light levels are used to make the main subject stand out and optimise curves or facial features. The image of Katie above is a prime example of this style.
The style was very popular during the Hollywood Golden Era and has, to a large extent, disappeared today. Modern portraiture tends to use high levels of light, filling the image with detail. I'll do a blog on this style at another time.
I like the combination of mystery and class that low key lighting evokes. The setting completely disappears from view in most examples. Our eye concentrates completely on the main subject and the photographer can manipulate the shadows to accentuate the sitter's features.
Low key portraits are much better at conveying mood also. In the shot of Katie she looks deep in thought, watching something in the unknown distance, while in the shot of Christina, above, the mood is one of disinterested, thoughtfulness, almost sadness.
Most low key portraits involve only one light, the key light. Shots like this one of Lee Anne, above, involve more. In this one I chose to use two hair lights, one from either side. All involve a darkened or black background. In each of the shots you've seen so far I've used a black background.
The final example, also of Katie, has much more light but it is highly controlled to ensure it only fell on Katie. The background is a good distance away from my model and no light falls on it. To make sure that I would get full effect of the low light I used a strong light on Katie that allowed settings that would not register light from the background.
While this is from the same session as the first I didn't use the black background, it's behind me. I wanted to experiment to see how dark I could get the room by using the settings in my camera. There would not have been a need to get it this dark under normal circumstances but there is a lot of equipment against the wall behind Katie.
So, there you are. I hope I've ignited an interest in you in low key portraiture. Many famous artists, like Rembrandt, used this style, as did film noir. It's much more evocative than other styles.
Until next time, take good care of yourself and those you love. Enjoy your photography and keep shooting.