Balancing light and color with artificial light
Overview
The steps of metering a scene for a flash
Color temperature
Using conventional wisdom to make creative color choices
Introduction
There’s many reasons wedding photographers today don’t use flash as much. You may have put off learning flash techniques because you didn’t like the “look” it gives photos. Perhaps it’s a space and cost issue. Or maybe, you’re like countless other photographers that feel intimidated by the complexity of flash photography. While I personally dove head first into flash photography at the beginning of my photography journey, I totally understand why photographers have these reservations. There have been plenty of dimly lit wedding receptions that I’ve preferred to shoot at some blisteringly high ISO. Cameras today can handle it much much better than they could just a few years ago. There’s also a lot of really bad flash photography out there. There’s a lot to consider when you shoot anything, adding a flash certainly complicates that. That all being said, there are some situations, and I know you can think of a few off the top of your head, where using a flash is the only way. When a flash is used really well, it imitates a logical light source for your scene. So whether you are using it to fake golden hour or cleaning up the look in your night time reception photos, I’m here to help you demystify flash photography.
I. Metering your scene
The first step to using a flash is something you’re probably already good at; metering natural light. How will you (or your flashes TTL) supposed to know how much light you need if you don’t know how much light you have. So the first step is to meter your natural light, both for exposure as well as color temperature (white balance). Something you need to keep in mind is that your shutter speed is going to the least important factor. Most cameras have a sync speed of 1/200-1/250th of a second. Newer camera models have HSS (high speed sync) but you’ll need to consider the toll that will take on your flash unit as it requires a ton of extra power from your flash. I try to avoid using HSS when I can. I lean on my flash systems a lot throughout a wedding day and it’s not going to put me in a good situation if I reach the half way point of the reception and my flash recycle time is a few seconds. (Rather than nearly instant). So let’s get back to the metering. As always, you’ll want to use the appropriate aperture for what you’re trying to achieve. Then set your shutter to 1/200-1/250th (depending on your camera’s sync speed) and then set your iso last. Meter for how you want your scene and your background to look. Sometimes I’ll meter my ambient light a stop or so under exposed as to make my lit subjects pop a bit more. Be conscious of all of the different light sources in your scene. Are you going to be moving around a lot? How does these scene change as you move? Luckily, when it comes to wedding receptions, your light should be fairly uniform throughout the space. If it’s not, that’s ok. You just need to be aware of any adjustments you’ll need to make for the scene. Also, be aware of color temperature. I always use the Kelvin settings in my cameras. This allows you to set your cameras white balance to a more precise color for your scene. We will get into color in the next section. So now that you have metered your ambient light, then all you’ll need to do is turn your flashes on and set the power of your flash to fit what you’ve set your camera to (not the other way around). I do use TTL (automatic flash power) quite often as I’ve found it to be really accurate and it’s one more thing I don’t have to worry about.
Understanding and matching color temperature
Different light sources emit light at different color temperatures. For example, the sun, on a clear day, meters in at about 5000 degrees Kelvin. Tungsten lights burn anywhere from about 2700-3200 degrees Kelvin. It’s really important to keep a constant eye on the color temperature of the scene you’re working in. It’s also important to be aware of what that light is touching. You may have sunlight bouncing off of a white wall with a warm tint. That’s going to change the temperature of the light. So you’ll want to be understanding the temperature of your light source as well as all of the bounced light. A lot of the time that flash photography looks bad it’s because the photographer ignored the color part of the equation. A prime example is sparkler exits. Sparklers burn off a light temp of about 2800 Kelvin. If your flash has a color temperature of 4500, that’s a huge difference in color temperature. Luckily, there’s a really simple, cheap, and quick fix; gels. Gels are plastic colored cards that you fix in front of the flash head to alter the color emitting from it. You can use a CTO (corrective tungsten orange) gel to warm up the color from your flash to match the color of the sparklers. You an apply this to a lot of different situations. You can gel a flash to match just about any color temperature.
Let’s bring this whole thing full circle; let’s say you’re shooting an outdoor reception. There’s a lot of bistro lights hanging over the dancefloor. They give off a little bit of light and you could get away with shooting it at a high ISO… but then the light on your subjects might not be so good. Let’s mix the flash with the ambient. First, meter your ambient light and color temperature. Let’s say you meter the scene as follows: 1/200th, f2, ISO 3200 / WB-3400K. All you need to do now is pick an appropriate modifier and gel for your flash and turn it on. Use a warming gel to bring the color temp of your flash from 4500 to 3400 and you’ll have an evenly lit and colored scene.
