How to Mix Flash with Ambient Light: A Step-by-Step Method
Can you think back to a time you were taking photos in a dinner scene and they just look “flash-y”? Why does flash never look natural? Well, in order to make flash look natural, you have to make flash part of the natural lighting scenario. Here’s how.
I admit, when I bought my first flash, not only did I not know how to mix it with natural light, I didn’t sync it properly. This resulted in a few film rolls being semi-exposed. It didn’t look good at all. So, if you already know how to sync your flash you’re better than I was.
The next step, a much-needed step, is making flash look natural. After all, if you’re taking photos at dinner, you don’t want your photos to look unnatural, as that often screams amateur hour. Professional event photographers can make their flash look like it’s not there.
While they’re still getting good light on subjects that results in sharp and clean images, that light looks like it’s part of the scene. This is called mixing flash with ambient light, and it’s a lot simpler than you might think.
In this article, I will share a step-by-step method to mix flash with ambient.
Gear
As this is a very interesting part for many photographers, I’ll cover this at the very start. Long story short, it doesn’t really matter… except that it does. In order to mix ambient light with the flash, you will need a set of color gels. Those are sold by pretty much every retailer and lighting brand there is on the market.
Profoto makes great gels that magnetize on its A1-series flash. I love using them as they are fast, practical, and hassle-free. They’re similar to what MagMod does. The only reason I mention Profoto is that I bought and use it on assignment — this is in no way an endorsement of the brand.
To prove my point here are two photos, one with Profoto gel and the other with a generic gel from Amazon:
There is an inconsistency between the two, which stems from the flashes having different color temperatures. However, as you can see, adding any gel to a flash does the exact same thing: it changes the color of the light.
Gear aside, let’s get to the actually interesting part of this article: the technique. Trust me, just owning all the gels in the world won’t make you any better, but knowing how to use them will.
Step 1. Identify the Lighting Scenario You’re In
The very first step you need to do is analyze where you’re at lighting-wise. The best way to start is to examine all light sources you can see. This may be a series of light bulbs, Christmas lights, the Sun, or nothing at all.
Once you identified the type of your lighting source, try to see what color it is glowing.
Commonly used light bulbs are rather warm, even if they appear to be white and normal. The reason they do is that we’re used to them, and many photographers are shocked when they see that their white flash didn’t mix perfectly with the “white” bulb.
A way to determine the color is to take a test shot. If there is any difference between the background color and the flashy part, you will need to then go ahead and see if the background is blue or orange.
Another way to see what temperature the lights are is to set your camera white balance to 5600K and fire a test shot. If the picture is orange, your scene is colder, while if it’s bluer, it’s colder (before you rip me apart for this statement, be aware that 3000K is orange while 8000K is blue, 3000K is a lot colder than 8000K).
The last part of analyzing your scene is looking at walls. If they’re anything but white, you will have a color cast. An orange wall will warm up the whole image while a blue one will cool it down just because it will reflect not white, but orange or blue light (the reason we see color is because surfaces reflect the light of different colors).
Step 2. Pick the Right Gel
At the start, this will be guesswork to a large degree. There are a few rules that can help you along the way, though.
First of all, if the room appears to be orange, you want to put a CTO gel on your flash. CTO stands for color temperature orange, and it will make your light warmer. In my camera bag, this is the most used of them all. Thinking back to my event days, I used a CTO any time I went inside, as 99% of the time, the lights inside are warmer than my flash.
If the setting is colder, go for a CTB gel. CTB stands for color temperature blue, and it will cool the light down. This is often the go-to gel for photographers working in nightclubs or in moody bars.
Afterward, if the room is anything different, you can add extra gels, such as red, to match the colors precisely.
The last step is to get the right amount of CTO or CTB or any other gel. There are full, half, or quarter gels. A full CTO gel will make your light incredibly warm while a quarter will be slightly noticeable but not too much. If you are in a candlelit room, a full CTO will be the right choice.
Step 3. Aim the Flash and Set the Power
The last step is to aim the flash. You have to be careful and considerate about aiming. First of all, evaluate how high the ceiling is. If it’s anything that is above 5 meters (17 feet) you may want to use a bounce card.
If the ceiling is too high, see if there are any other large surfaces you can aim your flash at — it can be a wall as well.
Depending on how close you are, and how large of an area you need to cover, set the power accordingly. More often than not flashes have TTL, so it is extremely easy to get it right from the first shot.
Closing Thoughts
Mixing ambient and flash is a core skill any photographer should have. Remember, there are three qualities of light: brightness, color, contrast. This article focused on color and brightness only, as getting contrast right is beyond the scope of basic ambient light mixing.
As a side-note, this would require you to examine the direction, size, and a lot more to really make your flash look like it’s coming from the ceiling or wherever the light source is. Over my years of shooting events, I rarely had to do this. It comes in handy where I am going for a certain aesthetic on a commercial job. But there I emulate ambient with flash from the get-go.
The biggest improvement you can make is truly getting the color and brightness right.
