If you would like to watch the video where I demonstrate this concept, CLICK HERE
If you’re passionate about photographing people, there’s one critical skill that separates professional-quality portraits from amateur ones: controlling contrast. No, this isn’t about tweaking sliders in Lightroom. It’s about nailing it in-camera with a reliable, repeatable process. Here’s a simplified guide to mastering contrast control through lighting ratios.
What Is Contrast, and Why Does It Matter?
Contrast is the key to creating visually compelling portraits. It defines the interplay between light and shadow, giving your subject depth and dimension. Proper contrast ensures your images don’t look flat or overly harsh—it strikes a perfect balance.
Lighting Ratio: The Secret to Controlling Contrast
A lighting ratio is simply the difference between the light intensity on the highlight side and the shadow side of your subject’s face. Understanding and applying this concept ensures you achieve consistent results in any setup—whether you’re shooting with constant light, flash, or natural light.
How to Measure Lighting Ratios
To measure lighting ratios, you’ll need to evaluate the light falling on your subject. The most accurate tool for this is an incident light meter, though you can also use your camera’s built-in meter.
Here’s how it’s done:
- Measure the ambient (shadow-side) light:
Turn off your main light and take a meter reading on the shadow side of the face. For example, this might give you a reading of f/1.4. - Measure the main (highlight-side) light:
Turn the main light back on and take a reading on the highlight side of the face. Suppose this reads f/4. - Calculate the lighting ratio:
The difference in stops between f/1.4 (ambient) and f/4 (main light) is three stops, which gives you a lighting ratio of 3:1.
Why Lighting Ratios Matter
By controlling the lighting ratio, you control the level of contrast in your portraits. A 3:1 ratio is a classic setup, creating a balance between depth and softness. If this is too contrasty, you can adjust by reducing the difference between your highlight and shadow readings.
Practical Applications
- Indoors or outdoors, start by measuring your base (ambient) light level.
- Add your key light and adjust its intensity to achieve the desired ratio.
- Always aim for consistency to make your results repeatable in future shoots.
Key Takeaway
Once you’ve identified the contrast level you like, all you need to do is ensure your key light is consistently offset by the same number of stops from your fill light. For example, if you like a 3:1 ratio, ensure your key light is three stops brighter than your fill light every time.