When buying strobes people mainly look at one number, the maximum power number, which is measured in Watt Seconds (ws) or Joules (j). This is perfectly natural. When talking about cars, maximum horsepower gets throw around a lot. After all we’ve been conditioned by marketers to want the fastest, most powerful toys out there. For good reason too, if you need to over power the sun for a portrait out doors, then you’ll need all the power you can get from a strobe.
Over the years I’ve used a number of powerful strobe systems and while the maximum power is necessary when using large modifiers, small apertures or when overpowering daylight; I’ve found it to be a hindrance at times as well. All strobes have a set power range, and on many strobes it’s a rather limited range at that. So if you have a whopping 1200ws to 2400ws on the high end of the range, you’ll usually have a low end of the range that’s still up there in power. Beyond the max power of a strobe make sure that you look into the kind of range it has as well.
For this reason I’ve had to travel to many shoots with both studio strobes and a bag full of small flash. Why would anyone need LESS power in a flash? What’s wrong with too much power? Two big things jump out as an environmental portrait shooter. It prohibits you from blending your flash with dim ambient light, and it also stops you from using your fast prime lenses at wide-open apertures like f/1.4 and f/2.8. Even when bottomed all the way out, some strobes still overpower the shot, and in the past I’ve had to bring out my tiny small flash and speedlights in those instances. That was until recently anyway!
I’ve been shooting with new Broncolor Siros 800 kit and it has proven to be versatile enough to fill both roles, in one sleek package. Lets look at a couple images from a recent shoot of mine with a documentary filmmaker in Brooklyn, NY. The first setup took place in the subject’s living room. His Shepard Fairey mural struck me as a great backdrop for the first portrait and I liked the ambient light coming from the two wall light fixtures flanking either side of the mural. I wanted a decent amount of depth-of-field to keep both his face and hands in focus, so I dialed the aperture down to f/8. You can see in the BTS photo that I modified my main Siros 800 with the included 2’x2’ softbox and even applied a warming CTO gel to the light, inside the box… so for anyone keeping track, the Siros has to expose for f/8 after going through a gel and the double diffusion of a softbox, all of which eat up light output. Needless to say I was thankful for the strobe’s 800ws max power here. Even when powered up, the fast recycle time allowed me to shoot at a quick pace to capture various expressions. The second Siros in the kit was used as a low fill light and to add a catchlight to the subject’s eyes. I then slowed down my shutter speed to allow the ambient background lights to become brighter in the final exposure of 1/60 sec f/8 ISO 400.
For the next shot we went outside onto the balcony. The walls were neatly textured with a wood paneling and lit by a single outdoor tungsten wall lamp. It looked neat to the human eye, but would be very dark to expose in-camera. The high ISO performance on my Nikon D4s is astounding, so we decided to make an environmental portrait out there using just the single tungsten bulb to light the scene. We ended up wide open at f/2.8 and ISO 2000 to get a proper exposure. I then wanted to add some fill light in from camera left. But with the camera lens wide open and a high ISO like 2000 anything more than candlelight might overpower the photo. Knowing that the Siros 800 has a huge power range we dialed it down 9 whole stops from 800ws to a minuscule 4ws… that’s WAY below the power of a common speedlight. After bouncing it into the wall of the apartment it turned out to be the perfect kiss of fill light needed to balance out the shot.