Tuesday, January 1, 2008

They Don't Call 'em Speedlights for Nothing...


Robert Benson, whom you may remember as having shot the SPOY 2nd Place photo of a woman on a beach serving a volleyball, today shows us his extreme range with this man serving a volleyball inside a gym. This multiple-exposure shot of a volleyball serve presents lots of problems to solve. But that's what makes it fun.

Robert eschews his big lights for this shot because (ahem) they were not fast enough. More on that, and how a couple of rim lights can gussy up some on-camera flash, after the jump.
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When doing a multi-exposure shot like this, you can go about it a couple of ways. First, a moving subject can be shot in a dark environment using an open shutter and multiple pops from the flash. The background has to remain dark, even with the strobes, or it will paint through other pops of the subject when it is at a different location. Side/rim lighting helps to define the subject against the dark backdrop in a nice, 3-D way.

The other method, which Robert used, is to shoot it on a series of different frames and strip elements from multiple sequences together in Photoshop. (You could also shoot a wider shot in any environment, locked down on a tripod, and clone the various versions of the moving subject into one "environment" frame.)

The use of off-camera flash in general, and speedlights in particular, solved a lot of problems for Robert. First, the light gave him a consistent, sharp-edged quality. Second, his back/rim lighting scheme gave him nice separation from the background. And the 9-frames-per-second speed was where the speedlights came into play.

If you want to have a bigger version of the shot up in another window as Robert walks you through the how-to, click here.


Robert explains:

Making this image was a little bit challenging. I've seen composites like this before. They were shot outdoors in bright light. The photographer motored through a particular sequence then stitched the photos together in Photoshop later. I did some of that, but the majority of this image was created in camera.

I wanted this to have more of a studio feel, and wanted to light it. I first thought about using some of my White Lighting strobes. But the problem was that even with strobes set at their lowest power, there was no way they would fire at nine frames per second, the speed on continuous high with my Canon Mark IIn.

Continuous light wasn't an option, because I wanted the motion-freezing light that flash gives. I also wanted background to remain dark, so subject would stand out.

So I tried Canon speedlights. I tested to see if one in master mode would make two other canon flashes in slave mode fire at nine frames a second. But even when set to their lowest power, they didn't keep up with 9 FPS.

So next I tried my Bogen radio slaves, but those didn't trip my lights every time in the 9FPS mode, either. They fired only at about four frames per second. So my only option, short of hard wiring the lights, were to use optical slaves, which were made by Wein and fit on the hotshoes of the flash. With one 530ex on the camera, it would trip the other two lights (one behind subject and one in front) at a rate of 9 frames per second!

But the flashes had to have very fresh batteries and be at their lowest setting (or almost the lowest setting) in order to keep up at that rate. The strobes were both on manual, at about 1/32 or 1/64th power -- not sure. They were about 6 feet in front of him and 6 feet behind (approximately). The camera was set at about 800, because speedlights were set so low.

Since they weren't putting out a lot of light, that meant the gym had to be nearly pitch black. (There was only a bit of light coming in through a cracked door.)

With camera on a tripod, I had him do his serve again and again as I motored through the sequence, flashes firing in unison as I shot, illuminating him with light.

Over the course of his two- to three-second serve the camera fired continuously, giving me all the different "phases" of his serve. In Photoshop I took the first frame (where he is at start of serve at the right of frame), then stitched in
the sequential shots of him only, into that first frame.

As I originally wrote, minimal Photoshop was used. The lesson I learned was that the only way to get multiple handhled strobes to fire rapidly in synch with the camera is to hardwire them or use Wein optical slaves (or equivalent).

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Reading Robert's shoot notes, a few things jump out at me:

1. This guy has access to the bigger lights, but they could not do what the speedlights could: Fire at an insanely fast cycle.

2. The ISO 800 thing: I do that a lot, too, to milk an extra stop or two out of my flashes. Well lit stuff at ISO 800 looks better than crappily lit stuff at ISO 400.

3. Looking at his photo, the main light is on camera. But the server still pops from those side/rim flashes at camera left and right. Direct flash does not look bad because of where it comes from. It looks bad because it gives no three-dimensional form to the subject. In conjunction with off-camera light, on-camera flash can be part of an effective lighting scheme. Call me crazy, but I kinda like the way the rim lights define the server against that ordinarily crappy direct flash wall shadow.


Thanks for the shoot notes, Robert. They illustrate very good problem solving, and the final result rocks. Check out the photo's Flickr page, here.

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