> 3 minute read

Working With Lighting Ratios

The ratio of flash to available light is a crucial factor in determining the look and feel of a photograph, and an important creative tool in a photographer’s arsenal.

Using flash outdoors in combination with ambient light is a good way to take control of lighting while keeping things looking natural. There are two ways to think about this technique:

• The flash is your main light source, with ambient light providing extra ‘fill’ illumination.
• The ambient light is your main light source, with flash providing the extra ‘fill’ illumination.

Which of these scenarios you choose depends on the look and feel you are going for – they are very different approaches.

Flash as main light source with ambient fill light

Ambient light as main light source with flash as fill light

It can help to think about these two approaches in terms of the lighting ratio between flash and daylight.

• A 1:1 ratio means the flash and daylight are given the same priority. This is achieved by simply turning on the flash and photographing as normal – use whichever shooting mode you like to get a correct ambient light exposure. The result is a balanced image where flash is evident, but doesn’t overpower the ambient light.
• A 2:1 ratio means the flash is one stop brighter than the ambient light. This is achieved by turning the flash on and photographing as normal, with -1 stop of exposure compensation set on the camera. In this case, the ambient light will be underexposed and the use of flash is more evident. This works well when you want to place a greater emphasis on the main subject, while retaining some detail in the background.
• A 1:2 ratio means the flash is one stop less bright than the ambient light. This is achieved by turning on the flash and photographing as normal, with -1 stop of flash exposure compensation set on the flash unit. Here, the flash output is less discernible, but you often get the benefits of using flash, such as a catchlight in the subject’s eyes.

Obviously, you can go more extreme with your ratios, like 3:1 or 1:3, by dialling in -2 on the camera or -2 on the flash respectively.

Ratio 1:1

Ratio 1:2

Ratio 1:3

Ratio 2:1

Ratio 3:1

Ambient light only

Flash only

Using flash as a fill-in source is good for photographing in bright, high-contrast sunlight, where strong shadows across your subject’s face can look ugly, and silhouetting can occur when photographing into the light. Whereas using flash as your main light source is a good way of overcoming boring, flat lighting when you want to inject some drama into your photography.

Your Next Steps

• CHALLENGE Photograph the same subject with different lighting ratios to see how many different looks you can create. Post the results to social media with the hashtag #learnwithfujifilm and #flash. You can also submit your work here for a chance to be featured on our social media channels.