How to Mix Ambient Light and Fill-Flash for Outdoor Portraits

If you have ever wondered how to improve your outdoor portraits. Turn off your Smartphone, shuffle your schedule, and make sure you read every single word on this page. Because outdoor portrait lighting secrets will finally be revealed.

Below is an example of one of my typical on-location lighting setups. It consists of a studio strobe with a battery pack and a Westcott 35″ Deep Parabolic Zeppelin modifier.

I am guessing you have most likely stumbled upon this article because you are searching for a way to improve your outdoor portraits. If you would like to capture perfectly exposed images in ambient light, the real secret is to use fill-flash and a light modifier. Sure, if you have a reflector and an assistant you may be able to achieve similar results using only natural light. But in this article, I am going to assume you shoot outdoor portraits by yourself and you are looking for the easiest way to control, and modify the light in your images.

Below is an example of an image taken with the above lighting set up, where I lowered the background exposure with a three stop neutral density filter.

Before we go any further, I just want to caution you, you may find some aspects of this article confusing the first time you read them. So I have included a video tutorial for you to further illustrate the lighting concepts discussed here.

Let’s break it down step by step:

Step #1 – meter the background

Step one is to meter the background area behind your subject, using either a light meter or your in-camera meter. For example, let’s say you metered the background at f/5.6 and you took a test exposure with your camera.

Step #2 – check highlights on the test shot

The second step is to examine your test shot and to make sure there are no blown out highlights in the brightest part of your image. Some DSLR models have a highlight warning indicator that you can enable and you can also view the Histogram to help you decide if your exposure falls within an acceptable range. The reason you are checking for blown out areas, is that once you loose detail in the highlights, the information from that part of the image is lost forever. So adjust your exposure if necessary to ensure you have an accurately exposed image with highlight detail intact.

Step #3 – check highlights on the test shot

Once you are pleased with the background exposure you may find that your subject appears too dark in relation to the background. Your next step is to match the foreground exposure with fill-flash. To do that, you can use either a speedlight or a studio strobe with the light modifier of your choice.

Let’s go into a little more detail. For example, if your background is exposed at f/5.6 then you have to match the same exposure on your subject’s face. Sounds simple right? Here is where you can run into some problems. If you meter the background at f/16 on a sunny day – then what do you do? Your subject will appear darker than the background. What are your choices?

In most cases your first impulse would be to raise the shutter speed, but when you’re using strobe lights you are capped at a shutter speed between 1/160 and 1/200th of a second. In some cases you may be able to use high-speed sync, but for the purpose of this article let’s say your maximum shutter speed is 1/200 (your camera’s native flash sync speed). If that is the case, you will have to use a two or three stop neutral density filter to lower the background exposure, so you can match the foreground exposure to the background.

Have I lost you yet? In case you find this concept difficult to grasp, I have included another video tutorial below on outdoor portraits using fill-flash, where I use a three stop neutral density filter to bring down the ambient exposure. In this example that allows me to use a wide open aperture, in combination with fill-flash to create a blurry background effect.

If you are like most people, it will probably take you a little practice until you feel comfortable balancing ambient light and fill-flash. Take your time and have fun with it. Read the article a few times and watch the video tutorials again. Once you have a pretty good grasp of the concepts discussed, head out and practice balancing your exposure. Some people prefer a background exposure that is one to two stops darker than their subject. Experiment with different ratios until you find a look that suits your style.

Please post any questions you have in the comments below.