As you might know, I shoot a lot of pretty girls. A lot of them are blonds. They range from dirty dishwater blondes to shiny, near-white, platinum blondes with all shades of blonde in between.
As you might also know, I shoot a lot of glamour and tease. Shooting glamour and tease means I often shoot with accent lights. Those accent lights require factoring in things like hair color (and more) when I'm setting and adjusting my lights. Blondes often present the most challenging subjects when it comes to accent lights.
The blonder the hair, of course, the easier it is to blow it out, exposure wise. Yet, I usually want to see pronounced highlights in that hair, even when it's platinum blonde hair. I'd like to say I'm always successful at doing so but, unfortunately, I'm not. Because of that, I'd rather err a bit on the side of under-exposure when I'm shooting blonde chicks. More so the blonder she might be. I should also note that it's fairly common for blondes to have paler skin. Often, the blonder the paler. Another reason erring on the side of under-exposure can sometimes be more of a blessing than a screw-up.
Digital photography is less forgiving than analog, especially when it comes to highlights. With digital, if you blow out the highlights there's usually nothing left, in terms of detail, to recover in post. That's one reason depending on RAW converters, rather than production exposure, will often fail you. This holds true whether you're shooting landscapes or female bodyscapes.
Here's a couple of things I usually do when I'm shooting blondes:
First, I try to keep my accent lights closer to the model than I might do if she's darker-haired. While that might sound counter-productive to not blowing out details in the highlights, remember that the bigger the light source (relative to the subject) the softer the light. That holds true for accent lights just like it does for main lights. If the light source is smaller (like it becomes the further the light is moved from the subject) it also becomes harder, harsher, and increases specular values. (You might also review Angle of Incidence/Reflection to help you understand how specular highlights work and what you can do, via positioning your lights, to mitigate them.)
Next, since the blonder the hair, the softer I generally want to see the highlights, it also means, (beyond keeping those accent lights closer to the subject) that I'll probably be using modifiers that are large enough to also help keep the light on the soft side. (Again, bigger being softer.)
Finally, the intensity of the light usually needs to be dialed down a bit. When shooting blondes, the contrast values I can get away with are generally lower than when I'm shooting darker-haired models. Why? Well, that blonde hair is often going to exhibit specular reflectivity in more obvious ways than dark hair will. That means greater probability of blowing out the highlights. I'm sometimes surprised, BTW, with how much light I have to throw at some dark-haired models to get some decent highlights going in their hair. That dark hair can really suck up an awful lot of the light! More so the darker and less shiny it is.
Anyway, just some stuff to consider next time you're shooting a blonde model, especially if she's more to the platinum side of blondishness.
The platinum blonde pretty girl at the top is Paris. I had to be careful to keep her hair from blowing out yet still maintaining some highlights in it while also providing distinct highlights on her body. For this set, I used medium-size strip boxes, either side from behind, for those accent lights. Obviously, I was also interested in enhancing the chiaroscuro factor. BTW, here's a short but good article on what constitutes good exposure. Click Here to read it.