Hi Friends,
Had the day off today, and took advantage of it to build something I’d been meaning to do for a long time: a multi-flash lightbar (which I’ve taken to calling my “Stro-Bar”-clever, huh?). The purpose is to be able to mount multiple hotshoe flashes (in my case, Nikon SB-800s) to combine output for situations where I need to work at higher than normal (1/250 sec) flash sync speeds. What situations might that be, you might ask…
For me, the most common application is what you see here – portraiture in bright sun. You remember the paper inserts that came with Kodak film? They suggested taking photos with the sun at your back. Fine for exposing your subject – if you like squinty eyes and boring sky. But, if you position your subject with the sun at his back, an available light photo gives you two options:
1: Nicely saturated sky, but silhouetted subject (ISO 200; 1/6000 sec; f/2.8):
Or, 2: if you spot meter for skin (e.g., face), you get nicely exposed subject, but blown out sky (ISO 200; 1/1000 sec; f/2.8):
So how do you get both a nicely saturated background with a properly exposed subject in this situation? The answer is flash (ISO 100; 1/1600 sec; f/2.8):
As a portrait photographer, aperture is key – a large aperture gives me a shallow depth of field, resulting in a nice, out of focus background, and keeping the attention on my subject. When shooting with flash, your shutter speed determines the ambient exposure – in this case, the sunlit background. However, to shoot wide open in bright light requires a really fast shutter speed – well in excess of the standard 1/250 sec. The solution is high-speed (FP) sync. Not all cameras / flashes are capable of this, but my Nikon system is, and I can shoot with flash at shutter speeds much higher than the standard 1/250 sec. The problem is that shooting above 1/250, while allowing me to underexpose my background, reduces the output of my flash units. So, in order to put enough light on the subject at higher than 1/250 sec, additional flashes are required.
Enter – the “Stro-Bar”. I will be the first to admit that the idea is not original. In fact, my friend, Bob, recently made one and was the impetus to finally do it myself as well. Now, with three strobes firing at 1/2 power, I’ve got enough light on my subject in direct mid-day sun to be able to drop my shutter speed to a point where I can underexpose the bright sky (which maintains the saturation), and still have enough light on my subject. (ISO 200; 1/6400 sec; f/2.8):
Construction is simple: a strip of aluminum stock, drilled with 1/4 inch holes to accept the 1/4-20 screws for cold shoes, and a 5/8 spigot to mount on a standard umbrella swivel adapter. I chose to use 1/6″ angle aluminum – seemed a bit more rigid than the 1/8″ flat aluminum strip. I cut the aluminum to 16″ length, and drilled the holes far enough apart to allow for mounting my Radiopoppers or PocketWizard FlexTT5 receivers. Use it horizontally or vertically. In the above example, it’s bare flash, but I suppose you could bounce it into an umbrella for a softer look. You’d need to bump up the power, however, given the additional distance / falloff for using a reflector. You could also use a shoot-through umbrella – less light loss than reflective.
Now, I’m looking for an outdoor, bright sun portrait opportunity! Bring it on, Sun!!!
Thanks for dropping by!
J
