Fill Light

Shooting subjects that are backlit creates a unique challenge so I’ve decided to kick off my blog by saying a few words concerning this very common issue.

Here’s a typical scenario: You’re on vacation and you want to take a picture of your other half standing in front of some spectacular view so you take out the camera and you snap a few shots. A few seconds later you look at the digital display only to observe that you’ve shot a dark silhouette standing before a nicely exposed background. What went wrong? So you try again to no avail and quickly convince yourself that there’s something wrong with the camera.

The answers to situations like this simply lie in understanding the camera. The camera has a built in light meter which unless you’re in Manual mode, will either influence the shutter times (Shutter Priority Mode) or the aperture (Aperture Priority Mode) in order to give you a perfectly exposed image. It reads all the light being reflected back through the lens and calculates what shutter speed or aperture or both (Automatic mode).

Notice that I used the term “reflected back through the lens” to describe how the camera’s built in light meter functions. So, in the vacation photo described above, if the background is very bright, the camera automatically figures your shutter speed or aperture or both in order to compensate. It doesn’t take into account the exposure of your significant other and therefore they become grossly underexposed.

There are a few things we can do. We can do what most professionals do and use an external hand held light meter to measure the light falling onto the subject instead of the light being reflected back at the camera lens or we can just make a few quick adjustments on the fly. Note that although a hand held light meter will give us the right aperture and shutter speed to perfectly expose the subject, it will do nothing for properly exposing the background.

Most cameras these days offer a “spot metering” mode which although is still measuring reflected light, at least it will try and evaluate based on a much smaller area of the frame, namely your subject. This sometimes solves the problem completely on its own but if you’re working with a camera that has no such metering mode and or this doesn’t solve your problem as far as the subject goes, there’s always plan “B”. Keep in mind that even when spot metering properly exposes the subject, you will still be left with an overexposed background.

Plan “B”: Simply open the aperture (smaller number) or decrease the shutter speed. Take a shot, look at the digital display and or histogram, evaluate the shot and repeat until happy with the result. Both methods will allow for more light therefore increasing the exposure on the subject but the background will inevitably range from being slightly to severely overexposed. So, if you don’t like the look of the overexposed background then don’t fret, there is still plan “C”.

Plan C: Use the cameras pop up flash or external flash in order to supply what is called “Fill Light”. Be familiar with the flash controls in order to either increase or decrease the intensity of the flash and take a shot, evaluate and repeat until satisfied. If shooting in Shutter Priority Mode or Aperture Priority Mode, the camera will evaluate the light entering the lens and then calculate the shutter speed or aperture in order to give you a perfect exposure. Therefore, the background will look beautiful but the subject may be underexposed if the background light is brighter. Using a slight amount of fill flash will remedy the problem and give you a perfectly exposed foreground and background.

The key to fill flash is to dial in just the right intensity. Until you’re familiar with your equipment, simply make adjustments by trial and error while keeping in mind that the right amount of flash is when it’s not obvious that a flash was used at all. If you can “feel” the flash then the intensity was set too high. Proper fill flash should leave us with a properly exposed background and foreground which looks both natural and appealing.

Furthermore, since this technique is a very useful tool for taming a bright background, with a few adjustments, it can also be used in situations where you want to purposely underexpose the background for artistic purposes or simply to make the subject stand out.

Results may vary from shoot to shoot depending on the lighting intensity difference between the background/foreground but with a little patience and some practice, nailing these types of shots will eventually become second nature.

There is yet another way to tackle this situation and have both background and foreground properly exposed without the use of flash. With the camera on a tripod and left in the exact same position, we would take two shots. One of the shots would expose for the background and the second shot would expose for the foreground. We would then merge the two images in Photoshop giving us the best of both shots. This is an interesting technique which consequently works best when shooting still life and also requires the use of a tripod not to mention advanced Photoshop skills.

In conclusion, the thing to remember is that when there’s a lot of brighter light behind the subject, the camera will render an underexposed foreground. Unless you want to shoot a silhouette or are intent on creating something artistic where you would like this type of result, the methods described above will help alleviate the problem. Using fill flash is the only practical way to properly expose foreground and background in this type of situation although it does require some practice and knowledge of your equipment. I strongly suggest starting by reading the camera manual, especially if you’re shooting with a recent digital camera as they have become quite complex in their attempt to integrate the latest technology and advanced features.

All techniques need to be practiced in order for them to be effective tools when the right moment arrives so go out and shoot and tune in again in a few weeks time for some more helpful tips and advice on how to optimise your photography experience.