As a photographer you know that great photos depend on great light. We also know that great light is either found or created. For portrait photographers the problem is that their subjects may not be available at a day or time that great light can be found, so it must be created. You can do this by using Off Camera Flash or as it is commonly known, OCF.
You could use the flash on your camera but that generally doesn’t lead to pleasing results. You aren’t able to create the beautiful shadows that are part of great light that way. On camera flash is very flat and straight on and, in most cases, that equals boring.
Taking the flash Off Camera gives many more artistic and pleasing possibilities, however getting the flash off camera and understanding how it works has been frustrating for many photographers. I’m going to break it down into some simple steps that I’ve found makes light bulbs go off in photographer’s heads (pun intended) and say “That’s it? That’s all there is to it? I can do this!”
For this exercise use Manual Camera AND Manual Flash. While TTL auto flash has come a long way it still tends to be very inconsistent from shot to shot. Once you see how relatively easy it is to do manual flash you will love its consistency.
• DSLR capable of manual operation
• Flash capable of manual power adjustments
• Wireless Flash Triggers (Manual Non-TTL)
• Portable light stand
• Light stand adapter to mount flash and umbrella/ softbox
• Diffuser, either an umbrella (reflective/shoot through) or a softbox
• Sand/Shot Bag to keep lightstand from falling in wind
Most of the top-of-the-line camera manufacturer flashes are capable of manual power adjustments. Many people also use inexpensive yet powerful flashes like the Vivitar 285HV or the Yongnuo YN560. You need a lot of power but not necessarily a lot of features.
For wireless triggers, the industry standard is the PocketWizard Plus, but there are many capable triggers for a fraction of the price that work reliably but just may not have the extreme range and rock solid build that PocketWizards have. They are available from such names as Cactus, Interfit, Paul C. Bluff and many others. Now that the equipment is together, let’s move on to the actual shooting.
Balance and Control
The trick to shooting portraits outdoors with flash is finding the right balance between the available ambient light and the light output from the flash. Knowing what part of your equipment controls what will help make that easy. To do that here are four main things to know:
1. Shutter Speed controls ambient light only
2. Flash Power controls light on the subject only
3. Aperture controls the entire scene
4. If you run out of room in either shutter speed or aperture, adjust ISO
Let’s break that down a little further for the “Why’s.”
Shutter Speed Only Controls Ambient Light
Because the flash happens in a split second−usually about 1/1000th of a second−the shutter speed has no effect on the flash’s exposure. So any adjustments made to shutter speed will only affect the ambient/ natural light in the scene. If your background is too bright relative to your subject, increase your shutter speed. Too dark? Decrease your shutter speed.
One important thing you need to know is the max flash sync speed of your camera. If you go past that sync speed in shutter speed you will see visible black banding on the bottom of your shot. For most cameras this is 1/200 or 1/250th. Check your camera manual.
One other setting needed is on the flash. Most go to sleep after a few seconds of non-use. In the custom settings, turn this feature off.
The other thing to consider is: what is the lowest shutter speed you can handhold your camera without visible camera shake? For most people it is around 1/50th of a second. But it depends on how long of a focal length lens you are using.
So with both of those known, you will see that the usable shutter speed range is limited to about 1/50 to 1/250th of a second.
In this example you can see the effects of only adjusting Shutter Speed and it’s effect on the Background only (Example 1).
Flash Power Controls the Light On The Subject
The flash is not capable of changing the ambient lighting in most cases so it will only affect the exposure on the subject. Subject too dark? Increase flash power. Subject too light? Turn down flash power. Remember also that another way besides the power control to adjust flash power is distance to subject. The closer the flash, the more power. The farther away, the less power (Example 2).
Aperture Controls The Whole Scene
Once you have established a good balance between the ambient light and the light on the subject, if global changes are needed to the entire scene, do that with aperture (Example 3).
Use Your ISO If You Run Out Of Adjustments
If it is getting darker outside and you run out of enough shutter speed to hand hold or if you cannot open the aperture more or it affects DOF too much, increase your ISO for more adjustments.
Putting It Together In Practice
The first thing you need to do is establish an exposure for the ambient light or the “background”. Because you are working with a limited shutter speed range you may find yourself shooting at a higher aperture than most portrait shooters are used to. They normally like shooting close to wide open to throw the background out of focus with a shallow DOF. This may not be possible given the shutter speed range. But you can celebrate the background and find interesting and beautiful backgrounds that become part of an environmental portrait.
Meter your background and meter the most important part of that background. If you want a beautiful blue sky or a sunset sky, make sure that is what you meter and set your exposure for.
With a good exposure for the background, turn to setting the exposure for the subject. Do this using flash power. There are two ways to find the right flash exposure: use a flash meter and meter the flash light falling on the subject and adjust the power of the flash till it is about the same as the ambient light aperture reading. Or, use the LCD on the back of the camera if you either can’t afford or fear that handheld light meters are complicated (they are not).
I usually tell people never to rely on the LCD of their camera because it isn’t accurate to judge exposure. But we are not looking for exposure−in this case we are only looking to see the balance between the ambient light and the flash illumination, and your camera’s LCD can be good enough to do just that.
If the subject is too dark, increase the flash power, if the subject appears “flashy” then lower the flash power till there is a nice balance between the subject and background.
After you get used to this balancing act of adjustments and what controls what, then it is time to start to work on refining your shots.
Try different flash positions relative to your subject to get interesting and pleasing shadows. Moving the flash closer to the subject will wrap the subject better and soften the light. Moving away will make the light source smaller and increase skin contrast.
Use different diffusers or even no diffusers. Sometimes if there is harsh light in the background you’ll want to use a more harsh light to make the scene look natural. You’ll want to put the shadows where you want them, not where the sun wants to put them.
Use scrims or diffusers to keep harsh ambient light off your subject, or place your subject in open shade with the sun hitting the background only.
Experimentation is the rule here and there is no end to what you can do, once you truly understand the controls.
Resources: Vivitar 285HV: vivitar.com; Yongnuo YN560: hkyongnuo.com; Impact Lightstand: bhphotovideo.com; flash/umbrella adapter: bhphotovideo.com; shoot through umbrella: bhphotovideo. com; Canon 580EX II Flash: canon.com; PocketWizard Plus II: pocketwizard.com