Magic Bullet Colorista IV

3-Way Correction: Shadow, Midtone, Highlight

The 3-Way controls change the color of the shadows, midtones and highlights for the image. The wheels are arranged in a triangle, with Shadow on the left, Highlight on the right and Midtone in the middle position.

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The 3-Way controls for color balance and luminance

The 3-Way wheels correspond to the color grading concepts of Lift (Shadow), Gamma (Midtones) and Gain (Highlights). 

Shadow wheel
Shadow sets the black level in the footage. Add density or darkness with adjustments to the Shadow color. Raise or lower the Shadow levels with its Luminance control. Offset the color balance in the Shadow regions with the Hue Point. Moving toward any of the colored regions pushes the color balance toward that color, moving from unsaturated at the center to completely saturated color at the edge.

Midtone wheel
Midtone changes the mid-tones in the footage, shifting the middle tones to be darker or brighter. For instance, to make an image warmer, move the Midtone dot toward the yellow/red area of the wheel — the more it's moved to the outside of the wheel, the warmer the image becomes.

Highlight wheel
Highlight sets the white level in the footage. The Highlight wheel will brighten and tint the entire image, but it mostly affects the highlights.

Anatomy of the color wheel

3way-wheelEach color wheel is divided into Hue, Saturation and Luminance controls.

  • Hue Point control that adjusts Hue and Saturation together.
  • Hue Shift control that adjusts Hue only.
  • Luminance gradient band along the right of each wheel.
  • Saturation gradient band along the left of each wheel.
  • The Hue Point control and the Luminance slider combine to set the target color.

 

Hue Point control

The Hue Point control is a dot inside the wheel. The Hue Point always appears as a 100% Saturation version of whatever color is picked.

Hue Point is a two-dimensional control because it affects both Hue and Saturation. It moves along the Hue axis and Saturation axis.

Hue Shift control

The Hue Shift control is a chip on the outskirts of the wheel. Red is its default color. As Hue Shift is moved around the wheel, it rotates the Hue Point dot along the center of the ring. The chip always reflects the exact color that it is sitting over.

Hue Shift is a one-dimensional control because it just moves along the Hue axis. This control adjusts the Hue of the selected color without changing its Saturation. This allows finer control and makes calculations more accurate. For instance, when working with skin tones and and the Saturation appears correct but the Hue is wrong, change the Hue only without touching the Saturation.

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At the top, adjusting the Hue Point control. At the bottom, adjusting the Hue Shift control to change Hue without affecting Saturation.

Saturation Shift control

The Saturation Shift slider is a color gradient with a white chip. Value range is 0-100%. Default value is 0%. Move the chip upwards to increase the Saturation of the color it is affecting. Move it down (towards gray) to decrease the Saturation of that color.

When its chip is in the gray area, the Saturation has gone towards white at the same Luminance level. When it's all the way towards the top, the color is at full saturation. Moving the Saturation Shift slider moves the Hue Point dot in a corresponding fashion, along the axis of most saturated to least saturated point of the same color.

Saturation Shift is a one-dimensional control because it just moves along the Saturation axis. Double-click the slider to reset its value.

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Top to Bottom, the Saturation Shift set high and low.

Luminance Shift control

The Luminance Shift slider is a grayscale gradient with a black chip. Value range is 0-100%. Default value is 0%. Move the chip upwards (towards white) to increase the brightness level of the image. Move the chip down (toward black) to decrease the brightness level.

Luminance Shift is a one-dimensional control because it just moves along the Luminance axis. Double-click the slider to reset its value.

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Top to bottom, the Luminance Shift set high and low.

Getting around the wheels

Here's some basic guidance and tips about working with the various color wheels:

  • The Hue Point dot moves very slowly as you click-and-drag. The extra sensitivity allows for more subtle adjustments to help concentrate on visually changing the image.
  • To move the dot to a specific location, click once in the wheel in a location that is distant from the control dot.
  • The center area of the wheel is mapped so that the Saturation moves very little as it moves from the center toward the edge of the circle. Visually, the wheel shows a linear change from white to fully saturated, but the saturation is not mapped linearly with change in position. This makes it easier to make relatively subtle color changes while getting good visual feedback.
  • Double-click the Luminance Shift or Saturation Shift slider to reset its value.
  • Double-click inside the color wheel to reset the whole wheel.

How Midtone/Gamma is calculated

The Midtone calculation protects changes in the Shadows and Highlights. In many other correction tools, when shifting the midtones, it inadvertently lifts the shadows and clip the highlights at extreme values.

In Colorista's Midtone calculation, there is a little toe at each end of the gamma curve that prevents it from touching changes to the absolute white and absolute black points. The gamma does a mathematically smooth curve, so the gamma change gives you a smooth result in the shadows and highlights, and protects them from data loss and radical adjustment.

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At left, a regular gamma is typically clipped at its white and black points. At right, our Midtone calculation blends at either side of the gamma.

Numeric Entry switch

Numeric Entry is an alternate way of looking at the 3-Way values. Click the switch icon to bring up an RGB display of the Shadow, Midtone and Highlight values, which is helpful for dialing in precise colors.

  • Each of the nine colors corresponds to a color dot in the wheels.
  • Numbers can be scrubbed to reach a value. However, the numeric value can't be typed in.
  • Double-clicking a number resets its value to 0.

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