Adjustment of Tone Curves: Brightness and Contrast

Brightness/Contrast Tab

The brightness/contrast adjustment uses the Brightness/Contrast tab of the Tone Curve Adjustment screen.

The Brightness/Contrast tab is composed as follows;

Name

Description

Brightness slider

Adjusts the brightness by moving the slider to left/right.

Brightness box

Specifies the value to apply as the brightness.

Contrast slider

Adjusts the contrast by moving the slider to left/right.

Contrast box

Specifies the value to apply as the contrast.

Undo

Discards the current settings of Brightness/Contrast tab, and returns to the last saved settings.

The result of adjustment of Brightness/Contrast can be adjusted additionally by operations to points on the curve in the curve view area of Tone Curve Adjustment. For details about how to operate the point, refer to Adjust with Point and Base Point.

Adjust Brightness and Contrast

This section describes how to adjust with Brightness/Contrast tab.

The brightness adjustment function is to adjust the tone curve by changing the middle point value of the brightness of the entire image. The brightness adjustment is the adjustment of the output value at base point where the input value (horizontal axis) in curve view area is 50%. When the slider is moved to the right (when the input value to the input box is large) the images is made brighter, and when the slider is moved to the left (when the input value to the input box is small) the image is made darker.
If you increase Brightness, colors become lighter.
The density of output for the density of input decreases.
If you decrease Brightness, colors become darker.
The density of output for the density of input increases.

The contrast adjustment function is to adjust the gradation for the bright part and the dark part of the entire image. The contrast adjustment is the adjustment of the output value at base point where the input values (horizontal axis) in curve view area are 25% and 75%. When the slider is moved to the right (when the input value to the input box is large) the contrast is made stronger, and when the slider is moved to the left (when the input value to the input box is small) the contrast is made weaker.
If you increase Contrast, colors become more vivid.
(S-shaped curve)
If you decrease Contrast, colors become more blurred.
(Reverse S-shaped curve)
For details, refer to Adjusting Tone Curves.

The adjustment using Brightness/Contrast tab adjusts each color of CMYK collectively. For details about each color adjustment, refer to Adjust the Tone Curve: Each Color.

  1. Click Brightness/Contrast tab on the Tone Curve Adjustment screen.

    Brightness/Contrast tab appears.

  2. Drag the Brightness slider to left/right. You can also set a value between -25 and 25 (inclusive) in the Brightness box.

    The value of the adjustment is reflected to curve view area and to preview of After Adjustment.

  3. Drag and move the Contrast slider to left/right. You can also set a value between -25 and 25 (inclusive) in the Contrast box.

    The value of the adjustment is reflected to curve view area and to preview of After Adjustment.

  4. Confirm the preview of After Adjustment, and repeat Step 2 and Step 3 as required.