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How to Tone Map HDR Images in Photomatix Pro

When you tone map your HDR images (convert an HDR image into something more manageable), the software fun starts to happen. The problem is that tone mapping is sometimes so unpredictable that showing you how to do it well is difficult. Every HDR image is different. The key is to experiment with the controls and then practice, practice, practice.

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General controls

The first section has the general controls. You can get to them no matter which section of the dialog box is expanded:

  • Strength: Controls contrast enhancement strength, both local and global. Although it isn’t technically the strength of the overall tone mapping effect, it acts like it. For a dramatic effect, raise Strength toward 100. Conversely, to create a more realistic effect, lower strength to 50 or lower.

  • Color Saturation: Controls color purity (which makes colors look either strong or washed out).

  • Luminosity: Affects overall brightness. Think of this setting partly as a shadow brightness control. Raising it brightens shadows, and lowering it darkens shadows.

    Contrast is also affected when you change the Luminosity setting.

    • Higher settings lower contrast.

    • Lower settings increase contrast.

  • Detail Contrast: Accentuates local contrast. The default is 0.

    • Higher settings amplify local contrast and darken the image. Can boost drama.

    • Lower settings reduce local contrast and lighten the image.

  • Lighting Adjustments: Controls the level at which contrast enhancements are smoothed out. This setting plays a large role in determining how the final tone mapped image looks. It’s also responsible for much of the debate over the “HDR look,” both good and bad. Smoothing comes in two modes:

    • Slider mode: Controls smoothing with a free-ranging slider. Higher values produce more smoothing, and lower values result in less.

    • Lighting Effects mode: Shows discrete buttons to control the smoothing strength.

    Each smoothing mode has its own, unique algorithm. Think of Slider mode as being beyond the maximum Lighting Effects mode setting.

    image1.jpg

More options

One section of the Details Enhancer dialog box has the tone settings. If you can’t see the section, click the arrow beside the name.

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This section has basic tone controls, as described in this list:

  • Smooth Highlights: Ignores the darker parts of the image. Use this option to blend areas where highlights and shadows meet.

    • Higher values tend to lighten the image.

    • Lower values tend to darken the image.

  • White Point: Sets the white point, or maximum luminosity, of the tone mapped image (the high end of the dynamic range).

    • Higher settings produce more contrast and a brighter image.

    • Lower settings produce less contrast and a darker image.

  • Black Point: Sets the black point, or minimum luminosity, of the tone mapped image (the low end of the dynamic range).

    • Higher settings make a darker, more contrasted image.

    • Lower settings make a lighter, less contrasted image.

  • Gamma: Sets the midpoint of the tone mapped image. Not every pixel is lightened or darkened by the same amount. You’re moving the brightness midpoint around, which squeezes or expands highlights or shadows into a smaller or larger space on the histogram.

    • Higher settings lighten the image.

    • Lower settings darken it.

  • Temperature: Change the color temperature of the tone mapped image.

    • Moving the slider to the right gives a reddish cast.

    • Moving the slider to the left gives a blue feeling.

Advanced options

This section of controls contains color settings. The following list describes the controls for the image’s color temperature and saturation controls for shadows and highlights:

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  • Micro-Smoothing: Smoothes details in the tone mapped image.

    • Higher settings result in a lighter, more realistic appearance and can also reduce image noise.

    • Lower settings perform little or no smoothing.

  • Saturation Highlights: Increase or decrease the color strength within the highlights of the tone mapped image.

    The Saturation Highlights control can be used as a tool to investigate the tonal regions of an image. Lower to the minimum amount, and then raise it to the maximum to see where the highlights are. You can also create different artistic effects.

  • Saturation Shadows: Does the same thing as Saturation Highlights, except as it pertains to the darker areas.

  • Shadows Smoothness: Smoothes shadows and ignores the brighter parts of the image. Higher values also darken the image. Use this option to blend the border where highlights and shadows meet.

    Neither Shadows Smoothness nor Highlights Smoothness controls are cure-alls, but they have a good effect if properly used.

  • Shadows Clipping: Sets the dark point where shadows are clipped (information is discarded). Raising this control can help fight noise in very dark areas by clipping them, which removes them from the tone mapped image.

  • 360 Image: If you’re shooting a 360-degree panorama, ensures that the left and right borders of an image are tone mapped in relation to each other.

Here is a final edited image, with raised Strength and Color Saturation, Luminosity, Detail Contrast, and White Point settings.

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