Allow me to tangent off once again to explain how I plan to compress this image’s exposure. When you press the camera’s shutter release the curtains that make up the shutter open up for a brief moment allowing light to fall on the sensor. During the time the shutter is open there are actually two exposures taking place simultaneously, at least in the context of this example. As you would expect, one exposure is taking place as the shutter opens up for the prescribed time you’ve selected for your shutter speed setting. But I’m also using a flash, and the pulse of light emitted from my flash happens in a fraction of a second at some point during the shutter’s time open, which in turn gives me another exposure I can use to my advantage. Whew! That’s a lot to take in if this is your first time hearing about this. The reason I mention this whole two simultaneous exposure thing is that it gives you an amazing tool to fix problems, and it’s just the ticket I need to fix my imbalance of shaded and lighted areas! I can set my ambient light exposure to capture the background light while simultaneously using the flash’s pulse of light to set the exposure of my subjects. Flippin’ cool, eh? Now I have control of the ratios of everything, to a certain extent at least, to create the goal image in my mind.
I set my camera’s shutter speed to expose the background to best meet my goal image. Then I start working on the speedlight’s exposure to capture the subjects in the light the best meets my goal image. Now I start the process of identifying problems with lighting my subjects with a speedlight, so here we go again.
I want to place the emphasis of the image on my subjects (ya, I know, obvious), so I need to deemphasize everything else. One of the tools I can use is to blur out the background by using the shallowest Depth Of Field I can get away with. But the more I open up my aperture the more light I’m letting into my exposure, so I have to compensate by setting my shutter speed faster to cut the light and placing the exposure back where I want it. The problem I have is that a flash’s pulse of light is so fast that it can happen while the camera’s curtains are still opening/closing and will block the flash’s light in part of the image. All cameras have a maximum shutter speed which they can reliably operate without blocking the flashes light referred to as the maximum sync speed, which in my case is 180th of a second. Knowing that I cannot go above 180th of a second for my shutter speed I am limited on how much I can open up my aperture while maintaining the correct ambient exposure, which in this case is f3.6.
With my ambient exposure now set I move on to the flash’s exposure. I want to pop just enough light on to my subjects to bring them in lighting balance with my background. It’s not too far off from the background at this time of day so I know it’s not going to take all of the watt seconds I have available to me, so I start with a single speedlight because I think that’s all I’ll need here to properly expose my subjects. New problem to solve, setting up the speedlight.
A speedlight, even when the flash head is zoomed out wide as possible, is a very small light source when compared to the size of the group of people I’m photographing. Not to be confused with light power or output, the size of the light source has a direct relationship with the contrast of your image. Let’s take the sun for example. It’s kind of bright, right? But it is 92,960,000 miles away from us (ya, I google’d that for you) which makes it a very small, although insanely bright, light source. This relationship of light size to subject size is what we refer to as relative size. The larger the relative size of your light source, the softer and less contrasty your light will be. In this case, my goal image dictates that I need a soft and less contrasty light source as I can practically achieve. So to solve the relative size of light problem that I have with a tiny speedlight I add a 43″ wide shoot through umbrella which turns the small, high power beam of light into a much larger, lower power panel of light more appropriate for the image I’m trying to create.
I place the speedlight and umbrella on a light stand to the camera’s right about 6 feet or so from my subject and take a test shot with the speedlight set to 1/4th power and it’s actually too much light which causes my subjects to be overexposed. To solve this new problem I have the option of dialing the power back to 1/8th power or moving the light stand away from my subjects, both will reduce the intensity of light on them. But if I increase the distance of the light source to my subjects I am also decreasing the relative size of my light source which defeats the point of the umbrella. Easy problem to solve, dial back the speedlight’s power.
Now that we understand that the distance of the light source affects the contrast and intensity of light cast on our subject, have you spotted the next problem I have to solve? The light source is not centered on my subjects which will produce uneven light across my group of subjects. I know, new problem I have to solve. I can move the light source to the center of the group which will distribute the light evenly over the group, but having the light source on the same axis as the camera will remove all shadows and create a very flat looking image that is out of sync with the light in the rest of the image and look very uninteresting. Might as well just us the camera’s flash! Nope.
I could setup another flash and umbrella which would even out the light on my group but then I have to spend the time to setup another light stand, flash, umbrella, power settings, etc. But I do have a better option available to solve my problem of uneven light, feathering. The light emitted from my umbrella can be thought of as cone of light that gets wider and dimmer as it moves away from the surface of the umbrella. If I simply rotate the umbrella so it’s pointed at the person furthest away it will illuminate them at about the same level as the edge of the light cone (which has weaker light) that falls on the closest person to the umbrella. Boom! Problem solved.
At this point my technical problems are solved using this continuous loop of identifying problems and then solving those problems. This is an ongoing process that pretty much “just happens” as I aim for my goal image. When you read over the process I just took you took you through it seems like a vast amount of time, mental energy, and conscience thought were expended to arrive at my goal image, and I guess in a way it is. But in reality when you think of it in terms of a series of problems and solutions, it’s really not so onerous as it seems. Most of this process just happens unconsciously as you get more experience and you can just intuit all of this as you survey the scene. All of the problems and solutions above took almost no time at all to work through, most of it was done in my head as we walked to from the parking lot.
One other thing that I’m working on in parallel with my technical problem solving routine is working on my rapport with my subjects. This relationship is as important to the final image as the technical aspects. Stop and re-read that last sentence one more time. If you skimp on the rapport with your subjects you are rolling the dice on whether or not you’ll get a great image. I could write an entire post on this subject (and you know I will) but just understand that you need to engage your subjects and start a running dialog that starts long before you press your shutter release. So with that in mind I start talking to everyone the instant we arrive and I even have some of them help me Sherpa my gear. It’s all about building trust and having them help carry my gear starts that process. Since the group includes children I weight a lot of the conversation in their direction and try to get them laughing if I can.
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