Growing up you would no doubt be advised that the best way to shoot portrait images is to place your subject facing the sun. While that approach does have some merits, because it tends to properly illuminate your subject, it has some serious downsides as well. For starters direct light can be unflattering. Plus, if you have carefully inspected your images half the time your subjects are squinting which is not a good thing for portrait photography.
The advantage of using the backlighting technique
Soon you would be wondering if there is a better way to shoot portraits in natural light. In fact there are a few. In this article I shall be discussing how to make portrait images using the backlighting technique. As the name suggests, backlighting involves illuminating the subject from behind. You would be wondering how you can get a proper exposure with the main light behind the subject. I shall come to that. But first you need to understand that the backlighting technique that I am talking about uses natural light. A slightly different approach is required for shooting in studio environment where the key light is placed behind the subject. That shall be discussed in a later article.
Backlighting allows you to capture those beautiful rim lighting that tend to separate the subject from the background. You may have seen this effect shot by other photographers, a beautiful halo of light that borders the subject’s head and shoulders, isolating it from the background.
Now before we jump into the process of using backlighting you need to know something about your camera’s metering system, especially the matrix (evaluative) metering mode. This is not the right mode to be used for shooting backlit portraits. With the background being brighter than the subject the metering system will be easily fooled into thinking that the scene is too bright and it needs to dial down the exposure. It would be right and wrong at the same time, because though the background is too bright, it is not the main subject. As such if it meters for the entire scene, the average reading and the resulting exposure will make the background brighter than the subject, which is not what we want. We want the subject to be properly exposed, regardless of the background illumination.
Using spot metering
There are a number of different solutions to this problem and we shall look at each of them here. The first solution requires you to set your camera to spot metering. Spot metering takes a reading of the area that is highlighted by the AF point. So it is also advisable that you select a single AF point which will give you an accurate reading. The background will be overexposed and the subject will be properly exposed.
Using exposure compensation button
The second solution is in using the exposure compensation button. Exposure compensation, as you might be aware of, is a sticky control. Once you have dialed in exposure compensation it stays that way affecting all your images unless you correct it again. So, be careful when using exposure compensation. Once your work is done don’t forget to reset it. Using exposure compensation is a good way to tell the camera what you want rather than going by what the camera says is the correct exposure. To use this first take a shot at the reading that the camera gives you. It is highly likely that the background will be brighter than the subject. Next, dial in some positive exposure compensation. You can select 1-stop positive exposure compensation to see how the results are coming up and then take it from there. Positive exposure compensation will increase the exposure making the subject properly exposed. It will also make the background brighter. Please note exposure compensation will work only when you are in one of the priority or creative auto modes. It will not work when you are in manual mode.
Using the AE-L/AF-L button
The third and final method involves using the Auto Exposure Lock or AE-L button. To do this take a reading off the subjects face by making a tight frame. Step forward, if you have to, so that you can crop out as much of the background as possible. Then when the camera has metered for the face only, step back, recompose and take the shot.
In some makes like the Nikon ones, AE-L is bundled with AF-L (or the Auto-focus Lock). So, when you press the AE-L/AF-L button it not only locks focus but also exposure. That means if you step behind and recompose you will need to manually adjust the focus, as it is bound to be off. Make sure that your lens has manual focusing override in AF mode before attempting this.
Another way to counter this issue is by assigning the AE-L/AF-L button to only AE-L and leave the auto-focusing to the shutter release button. To do this dive into the menu option. Go to Menu > Custom Setting Menu > Controls > Assign AE-L/AF-L button and select AE lock only. This is straight from my D7000 but should be similar to other Nikon models. For Canon and other makes please refer to the manual. When you select this option and press the AE-L / AF-L button only exposure is locked. Step back and press the shutter release button again to lock focus and fully press it down so that the exposure is made.
Some more tips
Backlighting works really well when you shoot the subject against a darker background. The contrasting background really brings out the rim lighting effect that much better. If you shoot against a bright background such as the sky or even directly shooting into the light the effect will not be that dramatic.
Speaking of shooting into the light, this is a problem if you don’t compose properly. Make sure that the source of light is slightly out of the lens’ field of view. Additionally, use a lens hood just to be sure that you don’t have any stray light creating flares. Flares and ghosts will bring down the contrast levels of your images. This tend to happen more with zoom lenses than prime ones, because the former has more elements inside them.