Last weekend Sarah and I headed into the woods to play with strobes and practice balancing them with ambient light. While we were scouting out the location and testing the ambient light, I got this shot of Sarah with a 50mm and a handheld reflector to give a nice catch light in the eyes:
Then we pulled out my Alien B800 and Vagabond battery pack. The main reason I was keen to do some testing was that I had recently bought a 1.8m softlighter. A softlighter is a large umbrella with a silver inlay which you shoot the light into for shape, but it also has a white diffusion panel over the front to soften the light up on the return journey. Being 1.8m big I assumed that this was going to give me a huge, soft, wrap around light source. The general rule with lighting is that the larger the light source relative to your subject, the softer the light. The sun for example, while bright, is only a tiny point in the sky relative to us, which is why it gives such harsh shadows. A big light source held close to the subject though will fill in shadows and give a soft, pleasing light.
So what I thought this big 1.8m light source would do was this:
But when I took a test shot what I actually got was this:
The light was soft, but it wasn't a big light source. In fact it barely covered head and shoulders. I was really confused for a while because this was breaking the rule I had learnt. It took me a few minutes but from what I could tell, this was what was happening:
Due to the fact that the umbrella is so shallow the light source was only bouncing off the centre and so creating a small light coming back through the diffusion panel. That diffusion panel may have been almost two meters big, but the light was only bouncing back through the very centre of it. The small reflection size, and the concave shape of the umbrella meant that I was left with a shot which looked like it had been lit with a snoot and a bit of ambient back lighting. I think it's actually a flaw with this particular product (Walimex 180cm Reflex Umbrella). Ideally the umbrella should have a deeper concave shape, so the light can sit further away from the inside surface, and so spread light over the whole surface and come back through the diffusion panel as large a source as possible.
Don't get me wrong, I actually like the shot. It was a happy accident and I stayed there shooting for a few minutes and got some great shots with that set up. But it wasn't what I had planned. I still wanted a bright ambient hair light from the sun, filled with a big soft light from the front.
So how did I get there?
Well first I had to slow down my shutter speed to let in more ambient light. The rule is, when balancing ambient light with strobes, that shutter speed controls your constant ambient light, and your aperture controls your strobes. Slowing down my shutter speed, means keeping the shutter open for longer and allowing more constant light in to the sensor. It doesn't effect the strobe though because it only fires momentarily within that shutter duration anyway.
I still had the same problem with the softlighter though. So I decided to pull the diffusion panel off the front and hang it spread out in the tree branches off to camera right. I then took my light and pulled it back so that the light would fall full across the surface of the diffusion panel without spilling past the edge:
This now meant that I had my large soft light from the front to fill. As a trade off I lost the shape of the light somewhat because Sarah was now only being lit by a bare strobe firing through a flat diffusion panel instead of being shaped by light returning from a concave umbrella, but it gave me the balance that I needed to get the shot I wanted. Which was this one:
So I used the sun coming in through the trees as a hair light, or rim light, and just balanced the strobe to fill in the front of Sarah's face. The trick with this kind of photography for me is to keep it looking as natural as possible, and I like the result of this one.
There are million ways to light. Once you get a sense for how it moves and behaves you can get a vision for what you want, and then work out how to get it. There are a slew of modifiers to help you get there too, from snoots to softboxes, umbrellas to beauty dishes, even just a white wall, or in my case, a diffusion panel hung from a tree. The point is to experiment and learn to bend the light through your lens and onto your sensor to get the shot you want.