The 90-Percent Rule—Part Four—Hair

Ever had a model show up with a bad hair day? Like most photographers your answer is probably yes, and if you haven’t, you will experience it. While some photographers normally hire hair stylists for a shoot, understanding the 90-percent rule can help ensure your subject’s hair will photograph beautifully, hair stylist or not—your model will also love you if her hair photographs healthy, beautiful, shiny and silky-smooth.

While this article is not designed to give you cosmetology lessons, it is an easy tip that will make you better understand light while creating more alluring photographs of your subjects, after all, hair can be sexy too!

First, let’s look at blonde hair. What is it really? Besides containing the model’s DNA, her hair basically is on the white, or lighter side of the 90-percent rule. Generally speaking, it will reflect more light than her skin because most blondes, natural or not, will have a hair color brighter than their skin and if you fail to see this, chances are you will blow out the highlights of the image. Like the clothing mentioned in Part three of the 90-percent rule (The 90-Percent Rule—Part Three—Clothes) saga, you can utilize black cards to tone the hair down and show more detail in the model’s hair—I did this when photographing April 2006 Playboy Playmate Holley Dorrough for the cover of my book, Garage Glamour™--Digital Nude and Beauty Photography Made Simple. Simply put, we had black cards surround her hair when she was photographed with one light and a 4- by 6-foot soft box.

While that book cover pose has her sitting and is a more of a vertical portrait, often photographers have real problems with blonde or platinum blonde hair when the model is lying on a bed or couch. A typical photographer will have the light at the end of the bed or couch with their shooting angle toward the other end. The problem here, the strongest part of the light hits the hair first before it hits the face as the light filters down. So for starters you might have an exposure of say F/8 at the hair and F/5.6 at the model’s chin.

Yes it can be this dramatic of an aperture change when the light source is a foot from the model because of the Inverse Square Law, especially if the model’s hair is flowing out toward the light and measures a foot or more in total length. The quick-fix is a black card directly above the hair and as close as possible to the hair while remaining out of the frame. The card can also cut the light away from the hair until you obtain less light on the hair than the face, as the face is what we should be properly exposing for in our glamour/beauty photographs.

Now let’s switch models to a darker brunette, in this scenario we’ll take the black card out and probably would not add a white card because the hair is already at F/8 while the face is at F/5.6. The darker hair is now absorbing more light than the face and should balance out when we properly expose for the face and not the hair.

Now let’s upright our brunette-haired model and pretend our background is dark. We can simply add a hair-light, usually with something like a 7-inch reflector with a 10- or 20-degree grid and aim it at the hair behind the model to add some rear highlights and separate her hair from the background. We can also place white cards on each side and the top of the hair to bring out the detail that can be lost in the shadows, especially if we’re only working with only one light.

In the case of my book cover, Holley’s hair was blonde and the background was semi-dark so we chose not to put any light on her from behind. A black card was placed above her head and tilted toward the front to add more detail, thus you can practically count the hair strands—only one light was used for the entire image. Some photographers will also take their soft boxes or light modifiers and raise them slightly higher than their subject and point the light down—thus the light hits the top of hair first and filters on down with less intensity.

A common mistake with “back-lit” hair is photographers making the light stronger on the hair than the main light, this is fine with brunettes or even darker hair, but not with blondes. Digital photography has no latitude for mistakes in the highlights, overexposed hair is easy to create with blondes because of the 90-percent rule. Most photo editors prefer properly exposed hair, face, skin, etc., and understanding that white reflects and black absorbs will help you better light any subject’s hair, improving your photography and separating you from the pack. Wishing you the best, rg sends!