D - E - F
I have an upcoming shoot with an actress who wants head shots. She's hiring a hair stylist and make up artist, and I'm pretty sure she knows way more about head shots than I do! I started researching head shot photography online, and realized I need to work on my lighting. So I enlisted model Charlotte, who agreed on the condition that she could nap through the whole thing. Note: all photos are unaltered, ie. no photoshopping to edit colors/brightness etc.
{see B} Currently, I rely on my external flash, mounted on top of my camera. I add a diffuser to it, one called a "lightsphere" which is not unlike a tupperware box of cloudy white plastic mounted atop a flash pointed towards the ceiling. This has the effect of producing a pleasant, soft light coming from the direction of the camera. You can't see much shadow, which flattens the image.
{A} Natural, window filtered indirect lighting is great, if it happens to be coming from the right direction, but in this case, I wanted her face to be lit from the left. The colors are rather muted.
{C} Direct camera flash is the Worst lighting option! Here, the flash points straight at Charlotte, no diffuser or anything. Unfortunately this is the only option available to point and shoot digital cameras, and DSLRs without external flashes. Harsh light, like deer in headlights. I do use this lighting for nightlife photography, but that's a different story.
{D} I read several articles that recommended bouncing camera flash light off a reflector. In this case, a large piece of white foam core, balanced on my tripod. I turned my flash to shoot in a 45 degree angle to my left, placed the reflector so that the light bounced and hit Charlotte's face. In the process some light is lost, so I upped the power on my flash. This method gives form to her face, and feels natural; it's not obvious that a flash was used.
{E} A mini-reflector (ie, small piece of cardboard) can be taped directly onto a flash. In this case, the flash pointed upwards, and the cardboard was placed perpendicular to the flash direction, facing Charlotte. As light doesn't have to travel far before being bounced onto the subject, the result is a rather harsh lighting also, but more diffuse than {C} ie, more evenly lit.
{F} Finally, flash pointing upwards towards white ceiling, light bounced off ceiling. It's a pleasant, soft light. This option only works if you have a white, low, ceiling. Has the disadvantages of creating shadows under eyes and chins, and seems less natural than a light coming from the side.
I think I like {D} the best. I can work on getting a larger piece of white board, so as to reflect more light, perhaps producing an effect like that of the ceiling, but from the side.