Understanding Highlight Detail

The best ETTR is achieved by exposing the highlights you want detail in as close to the right of the histogram as possible. That means what we are trying to do is hold highlight detail while exposing those highlights as brightly as possible. 

To help us understand this, let’s talk a little more about what highlight detail is. 

Highlights communicate important details, regardless of your style or subject matter. Picture a white wedding dress. Without highlight details, it’s just a giant white blank spot in the photograph. But with highlight detail, the fabric and all of its textures are revealed, which gives the dress form and shape. But highlights aren’t just white dresses. They can be weathered wood on tree branches, waterfalls, white painted fishing boats, and a whole host of subjects.

With digital cameras, highlight detail is controlled by exposure. Too much exposure and you don’t hold detail. But too little exposure causes you to be underexposed, with all of the problems that causes. 

Digital exposure is measured in pixel values. Light that strikes the sensor is converted into a number that defines the color and brightness of each pixel. But each pixel can only hold so many numbers. The pixels on our sensors are like rain gauges. When they fill up, they overflow and stop measuring. The result is a pure white pixel. 

Our goal is to make sure that we don’t overflow the sensor’s ability to measure in areas where we want to hold highlight detail. 

What we need when photographing is a way to accurately measure the highlight values so that we can evaluate and adjust our exposures appropriately. Learning how to do that is the purpose of this online workshop.