PremierePro

Adjust color and luminance using curves

The curves adjustment of the Luma Curve and the RGB Curves effects, like the Levels sliders in the Fast Color Corrector and the Three‑Way Color Corrector effects, let you adjust the entire tonal range or just a selected range of colors in a video clip. But unlike Levels, which has only three adjustments (black level, gray level, and white level), the Luma Curve and RGB Curves let you adjust up to 16 different points throughout an image’s tonal range (from shadows to highlights).

Opening a scope in a Reference Monitor that’s ganged to the Program Monitor lets you view the luminance, chrominance, or both values as you make the curves adjustments. If you’re using the Vectorscope, there should be minimal green shading in the areas outside of the center of the scope. Areas outside the center define the level of color saturation.
  1. In the Effects panel, click the triangle to expand the Video Effects bin, and then click the triangle to expand the Color Correction bin.
  2. Drag one of the following effects to the clip in the Timeline panel:
    Luma Curve
    Adjusts primarily luminance. Keep in mind that adjusting the luminance does affect the perceived saturation of the colors.

    RGB Curves
    Adjusts both color and luminance.

    Note: If a clip is selected in the Timeline panel, you can drag the effect to the Video Effects section of the Effect Controls panel.
  3. In the Effect Controls panel, click the triangle to expand the Luma Curve or RGB Curves controls.
  4. (Optional) Do any of the following to set preview options:

    • To view only the luminance values in a clip, choose Luma from the Output menu. This option affects only the preview in the Program Monitor; it doesn’t remove the color from the video.

    • To display a before and after view of the clip in one monitor, select the Show Split View option. You can specify whether the split view is horizontal or vertical by choosing from the Layout menu. You can also adjust the relative proportion of the before and after views.

  5. (Optional) Click the triangle to expand the Secondary Color Correction controls if you want to correct the exposure for a specific color or range of colors. Use the Eyedropper tool or the other Secondary Color Correction controls to specify the colors to correct.
  6. Do one of the following to make curve adjustments:

    • To adjust the luminance, click to add a point on the Luma or Master graph and drag to change the shape of the curve. Bowing the curve upward lightens the clip and bowing the curve downward darkens the clip. The steeper sections of the curve represent portions of the image with greater contrast.

    • To adjust both the color and luminance using the RGB Curves effect, click to add a point on the appropriate graph to adjust all color channels (Master), the red channel, the green channel, or the blue channel. Drag to change the shape of the curve. Bowing the curve upward lightens the pixel values and bowing the curve downward darkens the pixel values. The steeper sections of the curve represent portions of the image with greater contrast.

    You can add a maximum of 16 points to the curve. To delete a point, drag it off the graph.

    As you make adjustments, watch carefully for banding, noise, or polarization in the image. If you notice any of these, reduce the value you are adjusting.
View full size graphic
Original image (left), adjusting luminance (center), adjusting color (right)