High Dynamic Range

Simulate high-dynamic range imagery from a single image, using Capture One's High Dynamic Range tool.

Overview

The High Dynamic Range tool is designed to simulate high dynamic range imagery from a single image, and is not, as the name might suggest, meant to merge an exposure bracketing sequence consisting of multiple images.

While it is good practice to adopt optimal exposure techniques, such as ETTR, to minimize noise and maximize the sensor’s potential dynamic range to capture the widest range of tones without losing detail in the extremes, in reality the sensor’s dynamic range cannot be extended in a single image beyond its specification.

Adopting separate Highlight and Shadow sliders, the High Dynamic Range tool therefore compresses the extreme tonal values in an image to simulate a wider dynamic range.

The Highlight slider lowers the brightness in the highlights and is used to recover detail from overexposed regions. If a channel is clipped accidentally, the tool can use the data in the other channels to reveal detail.

By analyzing the color data in the shadow regions, the HDR tool's Shadow slider adopts similar technology for determining and recovering detail that's no longer visible from underexposed images. As the brightness is increased in the shadows, excessive adjustment should be avoided where possible, otherwise noise is likely to become visible.

 

 

 

Auto Adjust HDR

The High Dynamic Range tool has an Auto option available from the tool’s title bar. Like the other Auto Adjust options in Capture One, this is can be enabled from the main tool-bar and added alongside other adjustments and included as an option when importing.

It is also useful as an initial setting, as the tool’s sliders are updated with the adjusted settings. Not only does this show the amount of adjustment for the image, giving you some indication of how to use it, but also allows you to fine tune the image afterwards.

The Auto option automatically analyzes the image and optimally adjusts the highlight and shadow regions. Providing the image isn't grossly over- or under-exposed it typically has little effect on mid-tones. This usually results in natural-looking images and provides a good starting point for images with clipped channels.

  1. Go to the Exposure Inspector.
  2. From the High Dynamic Range tool’s title bar, press the A icon. Where necessary, the adjustments are automatically applied to the image, and the Highlight and Shadow sliders display the adjustment settings.
  3. Fine tune adjustments using the two sliders. (Enable Show Exposure Warnings in the tool-bar, main menu or using the shortcut Cmd/Ctrl-E).

Recover detail in the highlights and shadows

The Highlight slider is used to restore detail from highlights by compressing the color and luminance values at the right hand side of the histogram.

The Shadow slider lightens the deepest shadows, compressing tonal values at the other end of the range, revealing any detail that was recorded at the time of capture.

The HDR tool produces natural looking images at low-to-medium values. Note that excessive adjustment can lower both contrast and saturation. It is recommended, therefore, that the Clarity tool is used to add mid-tone contrast.

The tool is placed before the Levels and Curve tools for a reason. At the risk of revealing noise, the HDR tool should not be used after adjustment of those tools in your workflow.

  1. Select the image or images to be adjusted in the Browser.
  2. Enable Show Exposure Warnings in the tool-bar, main menu or using the shortcut Cmd/Ctrl-E.
  3. Go to the Exposure Inspector.
  4. From the High Dynamic Range tool, adjust Highlight slider to darken and recover bright and over-exposed areas while observing the highlight warning mask. Specular highlights, reflections and direct light sources can be left to clip.
  5. Adjust the Shadow slider to lighten dark areas to reveal detail as necessary. Keep to low values to maintain natural looking images.