Five Tips for Photographers Using Off-Camera Flash

By MagMod

October 31^st, 2023

When photographers first jump into flash photography, they soon discover there’s a lot to learn. It can feel overwhelming at the beginning, but with a few helpful tips, as well as some user-friendly gear and time spent practicing techniques, it shouldn’t take long to master the basics.

Off-camera flash (OCF) photography opens up heaps of new creative possibilities, and in this article, we’ll share five OCF tips that you can put to use right away.

Video: Five Tips for Photographers Using Off-Camera Flash

Gear Checklist

Here’s a quick overview of the gear used in this video/article. Use whatever you have available to you:

Profoto A1
Profoto B10
MagSphere 2
MagBox Pro 24” Octa
Pro Correction Gel (CTO)
Camera (Canon R5)
Lens (Canon RF 70-200mm f/2.8)

Let’s get started.

Tip #1: Shoot with Manual Flash Power

When shooting in Auto mode (otherwise known as ETTL or TTL), the flash will choose the power for you.

This means that every time you fire the flash, the flash power can change, making it difficult for you to understand why it sometimes looks good and other times does not. The exposure might be too bright, too dark, or even occasionally just right.

By changing the flash power to Manual, you’ll get consistent power every time and you’ll understand how to use flash more quickly.

You’ll also save a lot of time in post that you’d otherwise spend trying to balance the exposure across a set of photos.

The most important thing to remember when manually setting your flash power is that flash power is generally measured in fractions.

In other words, the lower power has a higher number in the bottom of the fraction.

For example, a 1/64th power setting would produce a less powerful flash than a 1/32nd or 1/16th power setting.

When in the Sun, Shoot One over One

Here’s a simple “rule” to help you get started with manually setting your flash power:

When in the sun, shoot one over one. This means that you’ll typically start with a full power setting (1/1) when doing flash photography on a sunny day, especially when diffusing the light with a flash modifier.

Five Tips for Photographers Using Off-Camera Flash

Here’s a behind-the-scenes look at the setup with the flash (and MagSphere 2) placed just off to the side of the seated subject:

And here’s a look at the final, edited image (right).

70-200mm at 100mm, 1/4000, f/2.8, ISO 100 | Flash Power = 1/1 (Full Power) | Edited with Visual Flow Presets

Use the Inverse of ISO as the Starting Point for Adequate Flash Power

Another simple rule that we can use to determine a good starting point for setting our flash power is using the inverse of our ISO setting as a reference. Here’s a basic breakdown:

ISO 200 | Start at ½ power
ISO 400 | Start at ¼ power
ISO 1600 | Start at 1/16 power

Tip #2: Get to Know the Inverse Square Law

Speaking of inverse numbers, another great tip for using off-camera flash involves the inverse square law, and it plays an important role in understanding how much light is reaching your subjects, especially when photographing large groups of people. Don’t worry, it sounds more complicated than it is.

The basic idea is that the intensity of your light falls off rapidly as you move it farther away from your subject.

For example, if you place your off-camera flash 3 feet away from your subject, and then you move it back another 3 feet (meaning it’s now placed 6 feet away from your subject) at the same flash power setting, then less light will fall on your subjects. In fact, only 25% of the light that was reaching them at a distance of 3 feet will get to them from 6 feet away. By doubling our distance, we lost 75% of our flash power!

Why is that? Great question.

If you double the distance, say from 3 to 6, then you have increased the distance by 2x. The inverse of 2 is ½. Square that (multiply the number on the bottom of the fraction by itself - 2 x 2), and you get ¼. That is why they call it the inverse square law. For another example, let’s say you’ve increased the distance between the flash and your subjects by 3x. Using the inverse square law, we know that the inverse of 3 is ⅓. When we square ⅓ we get 1/9.

We can compensate for this light loss in different ways, including boosting our flash power as well as funneling the light more directly toward our subject using a grid (like the MagGrid 2) or even the flash unit’s built-in zoom feature.

Tip #3: Understand Soft Light vs Hard Light

Whether you prefer soft light or hard light doesn’t matter. Both styles of light work. What does matter is that you understand the difference between the two and that you light with intention to get the look you want.

Soft Light

If you prefer soft light, then you will likely want to use a softbox. The key is making your light source big. If you move it in close, the light source gets bigger, relative to your subject.

A good rule of thumb is to keep the flash about one to two times the distance from your subject as the size of the box. So, for example, if you have a MagBox Pro 42” Octa, keep it between 42” - 84” (3-7 feet) away from your subject.

If you’re using a smaller box, like the MagBox Pro 24” Octa, try to keep it between 24”-48” away from your subject for the softest light.

Hard Light

Now, if you prefer hard light, go ahead and move your lights farther back or use other smaller modifiers, like a MagSphere, MagBounce, or MagGrid. Even the new MagSphere XL might provide a nice balance, but it really depends on the distance between your light and modifiers are from the subject.

Whatever the case, be sure to use some kind of modifier to help modify and control your light. You’ll like the results a lot better than using bare flash.

Tip #4: Add Color to Your Flashes

Want to have fun and impress your clients? Start using color on your flash. By using color gels on your flash, like the MagMod Pro Gels, you can easily transform an otherwise bland scene into something wild. The only limit, really, is your imagination. From adding one additional color behind the subject to using multiple colors, you can come up with countless variations to add visual interest to your photos.

The video above demonstrates how to use creative color effects with MagGels to change the color and mood in your photos. It also covers which gels to use to get the exact color you want for your scene, regardless of the ambient colors that are already present.

Tip #5: Use Multi-Light Setups

Once you feel like you have the hang of using one off-camera flash, consider investing in a second. If you do, you’ll soon discover that your lighting setups get even more fun and you love the results even more. By using two lights, you can put one at full power and the other at half power to create a nice contrast effect. Adjusting these ratios can change the mood and depth of your photos.

One good place to start is just by placing your second light behind your subjects to create a rim lighting effect. This second light behind them that carves them from your background will help take an ordinary photo and make it extraordinary.

In the photos above, we can see how one extra light works to edge subjects out in the scene.

Here’s a final, edited image made using the two-light setup (see above).

Conclusion

Hopefully, you found these five tips for using off-camera flash helpful and can immediately put them to use. With a basic understanding of flash functionality and the help of portable, easy-to-use light modifiers, you can take creative creative control of your photo sessions and more easily match your vision with your final images.