Learning to Light White

Tonight I stayed after work to shoot some corporate images of my friend Connie. Connie teaches our corporate staff the ins and outs of giving top notch presentations. I must say that while watching her teach a seminar, she's impressive. And she's very nice too. 

Connie needed images of herself showing her gestures and mannerisms while teaching a presentation class. Each image will be part of a PowerPoint presentation that she uses to teach her online webinar presentation classes. I asked my friend Jerry, who's a pretty good photographer in his own right, to assist. 

I decided to photograph Connie on a pure white background as this would allow each image to seamlessly blend with the white background in her PowerPoint slides. Jerry and I chose a large conference room where I set up two White Lightning Ultra 1600 strobes (WL) with Pocket Wizards in the middle of the room about 15 feet from the background, which was a white seamless wall. I used a 47" Octobox in one of the strobes; the other in a 36" softbox. Why not use two Octoboxes? Because I only have one. I was looking for nice, even lighting across Connie, which is why I decided on the big boxes. 

Next, I set up one Nikon Speedlight with a Pocket Wizard about 4 feet from the background wall, aimed directly at the wall. I set the power to 1/2 power. Why the Nikon Speedlight? Because I wanted to see if I could use both the White Lightnings and the Speedlights in conjunction with each another.

Conclusion? Yep, you can use hot shoe flashes in conjunction with heavy duty studio strobes, as long as you power back the studio beasts. I mean, a hot shoe flash at full power will never put out enough light to compete with a studio head, so to balance them successfully, the studios must be powered back. 

At this point, I began by setting my exposure for my subject by having Jerry stand in as Connie, who had not yet arrived. I randomly chose an aperature of f/9 and a shutter speed of 1/250. I then shut off the overhead ambient florescent room lights and used the WL modeling lights to see how the potential WL strobe lighting would look on Jerry. Because the WLs are monster strobes, I knew I had to dial back the power on each head. After taking a few meter readings, I settled on 1/8 power with each WL about 3 feet from my subject. That gave me my working aperture of f/9. 

At that point, I shut down the WLs to work on the background lighting with the Speedlights. To get the pure white background I wanted, I knew the background exposure at the wall needed to be 1 1/2 stops over the key light exposure of f/9. That would give me a background exposure reading of about f/16 - almost twice as bright as my keylight exposure of f/9. At f/16, the background exposure is a bit more than 1 1/2 stops; more like 1 2/3 stops. Pretty close though, so I went with it. 

When I actually turned the Speedlight on and set it at 1/2 power, my incident reading showed f/5.6 -  about a stop and a third underexposed. Not good. So I cranked up the power to full and tried another reading again. This time I got f/8. Still not enough light. However, had it BEEN enough light, at full power, I was concerned that I would have sucked the life out of its batteries had the photo session gone longer than planned. 

At this point, my option seemed like it was time to set up another WL because I needed the power. But I'd seen other photographers use two Speedlights together to increase the flash output so I thought I'd try that first. 

I added a second Speedlight with a Pocket Wizard next to the first and dialed them both back to 1/2 power, and then took a reading. Whoa, f/22! Too much light, but now I knew I wouldn't need the other WL. I dialed down both Speedlights to 1/4 power and took another reading. This time, pay dirt! f/16. 

Next I went back to where Jerry was standing and took another incident light reading at the back of his head. Remember, I had a working key light aperture of f/9 and I needed f/9 at the back of his head to keep light wrap to a minimum. In fact, I really didn't want any wrap. When I took the reading, I got a reading of f/5.6, which was a bit underexposed, but that aperture probably would have worked. Jerry and I discussed this and we decided to go for f/9, so we moved our subject spot back a couple of feet, towards the Speedlights. Doing this gave me a reading of f/9 at the back of his head, while maintaining a wall exposure of f/16. Perfect... 

Now it's time to get started with Connie. Connie came in, took her position and we began the session. All told, the session took about 15 minutes, which was good, because Connie was meeting friends for dinner and she didn't have a lot of time. It was also good because this was an actually a REAL session, with a REAL customer, who had REAL deadlines to deal with, which gave me a limited time to work. Just like in the REAL world.

The final images looked OK, but there was one problem... too much light wrap on Connie's left arm. After analyzing the image, I realized that the problem occurred because one of the Speedlights was exposed. By that I mean, it had nothing shielding the massive amount of light coming off the wall. The left Speedlight had a gobo (Go-Before-Optics, or Go Between) in front of it -- and that gobo was Connie herself. With her black outfit, she was actually absorbing some of the light bouncing off the wall and that kept the light from wrapping around her. Her right side is well-exposed, with no wrap at all. However the right Speedlight had nothing blocking it so all that light came off the wall, right back at her, and then wrapped itself around Connie's left arm and side. Check out the image to the left for the details. No big deal to solve, as it simply means in future sessions, I'll put up a couple of black panels on each side of the set and angle the lights at the wall from behind the panels. Note to self: MUST USE GOBOS. 

So that's it. I was very happy with the shoot, as I learned that lighting is all about numbers. If I work the numbers correctly, the pictures will turn out as I envision them. 

Just as Dean Collins taught. 

 -30-