How to Turn a Background Black with Speedlights

I was recently inspired by a series of portraits by Alexandria Huff. Titled “Chiaroscuro Portraiture,” it features these gorgeous close-up portraits of the men and women in her life, each one of which is a study in how to render the interplay between light and shadow.

Alexandria sometimes takes these images in front of a grey background and, through a combination of getting in close to her subjects and using one light, sends what little you might see of that grey to almost pitch black. Her technique allows her to shoot just about anywhere, even when there are no dark backdrops available. I began to think of what I could do if I didn’t have a backdrop to shoot against and I needed to make a lower-key portrait in a relatively brightly-lit area. In theory, it could be done; a basic understanding of the Inverse-Square Law reveals that much.

But what if all you had was a basic modifier and a couple of Speedlights – not a big studio strobe? Could you still do it? I had to give it a try.

I picked the area above to try this out in. That’s the BorrowLenses lobby. As you can tell, it’s a pretty bright area, with large glass windows letting in a lot of ambient light, grey walls with photos mounted, a television and a glass case in the corner. Not exactly an “uncluttered” background but it made for a great area for testing. I roped in a couple of guys from the BL team to be my portrait subjects. They’ve been long-suffering models for my various experiments.

I started with taking a test exposure. I knew I wanted to kill the ambient light completely, so I took a test shot at a shutter speed of 1/250th at f/8 at ISO 100 and, sure enough, the exposure was completely dark. Then, I put Andrew in front of the camera with one Nikon SB-910 Speedlight in a softbox to his left (camera-right). The box was aimed at a roughly 30º angle.

This resulted in the image below.

The background was definitely not black. I suspected that the flash was spilling onto the background but I wondered if it could possibly be ambient leaking into the image, despite my earlier shot of just the room at the same settings. I decided to give it another go, this time upping my shutter speed (which controls the amount of ambient light in the exposure) to 1/640th and using the SB-910 in Auto-FP (high speed sync) mode, which lets you shoot at shutter speeds all the way to 1/8000th on a D800E.

At this point, it’s pretty obvious that there’s no ambient light leaking into the shot. But what the heck, let’s be totally sure. Here’s the shot at 1/1250th at f/4.

Much darker, but you can still tell that the background isn’t pure black. Also, Andrew is much darker than I’d like. Nothing I can’t fix in post but I know there’s a way to do this all in-camera. Now I’m certain it’s not the ambient light, so I dial back down to 1/250th and reposition the softbox.

This time, I’m basically feathering the light source away from the background as much as possible, skimming it across Andrew’s face.

Depending on your computer, you may or may not see that the background isn’t yet completely black. True, if I up the contrast in Lightroom just a bit, and tweak it a tad, I’ll have my desired result. But it’s not in-camera, darnit! So I changed things up. I switched from a Lastolite Ezybox Hotshoe to an Apollo 28″ Softbox with a Lastolite TriFlash. The Triflash lets you put two Speedlights, like the SB-910s I used, onto a single light stand so you can get an extra stop of power out of it.

With two Speedlights in the Apollo, I brought the box in just a bit closer to Andrew and added one more element to the mix – a reflector on camera-left with its black side facing Andrew. Also known as a “flag,” its purpose was to prevent light from the softbox from caroming around the room. I also upped my aperture from f/8 to f/16 and stepped closer to my subject, increasing the effect of the aforementioned Inverse-Square Law.

And the result, at 1/250th, f/16:

That totally did the trick. As you can see, the background is completely black, with rich shadows and soft light creating a very Huffian (as in the aforementioned Alexandria Huff) portrait.

I brought Ben up in front of the camera so I could make sure my setup was replicable.

Apart from a small retouch on their faces to sort out tone, the above images are pretty much straight out of camera. As an experiment, I repositioned the softbox a bit to get a nice split-lighting image with Ben as well. I had to “dodge” a tiny gleam out of his right eye that I suspected came from the on-board flash of the D800, which I used to trigger the SB-910s, but that was it.

This experiment is just one way to fade the background to black. There are other ways as well – using an ND filter with large studio strobes, using high speed sync, etc. Either way, it’s nice to know that with just a couple of Speedlights (or just one, if you’re willing to do a minimal amount of post-processing) you can create striking, dramatic portraits regardless of where you are.

And here, for giggles, as an example of the dynamic range that a D800E is capable of capturing, is the image above of Ben with the exposure brought up by 4 stops.

Um, yeah.

As always, questions and feedback are welcome in the comments below.