The Autodesk Control Surface > Performing Colour Grading >

# Logarithmic Mode

When Log is enabled in the Setup Grade menu, the Colour Grading panel and the Function panel are activated with logarithmic colour grading functionality.

Grading in Logarithmic Mode Using the Colour Grading Panel

Use the Colour Grading panel to:

- Adjust brightness balance and contrast balance for the entire image or for a range of colours.
- Adjust brightness in the shadows, midtones, and highlights.

There are two available setups for the Colour Grading panel. You can switch between setups by pressing the F9 button.

The default setup allows you to modify contrast, overall brightness, and brightness in the shadows, midtones, and highlights. Adjusting brightness in the shadows, midtones, and highlights requires that you switch the functionality of the first trackball among the three. You use the second and third trackballs to adjust contrast and brightness in the overall image.

The alternate setup distributes brightness controls for the shadows, midtones, and highlights amongst the three trackballs. This allows you to balance the values without having to constantly switch the functionality of a single trackball.

To colour grade using the Colour Grading panel default setup:

1. On the Colour Grading panel, use the following controls.

   Use: | To:
   --- | ---
   First ring | Adjust brightness in the shadows, midtones, or highlights for the overall image. To reset, press F1.
   First jog ball | Adjust brightness in the shadows, midtones, or highlights for a range of colours. To reset, press F2.
   F3 button | Switch functionality for the first trackball between shadows, midtones, or highlights.
   Second ring | Adjust contrast/pivot in the overall image. To reset, press F4.
   Second jog ball | Adjust contrast/pivot in a range of colours. To reset, press F5.
   F6 button | Toggle functionality for the second trackball between contrast and pivot.
   Third ring | Adjust brightness in the overall image. To reset, press F7.
   Third jog ball | Adjust brightness in a range of colours. To reset, press F8.

To colour grade using the Colour Grading panel alternate setup:

1. Press the F9 button to switch to the alternate setup.
2. On the Colour Grading panel, use the following controls.

   Use: | To:
   --- | ---
   First ring | Adjust overall brightness in the shadows. To reset, press F1.
   First jog ball | Adjust brightness in the shadows for a range of colours. To reset, press F2.
   Second ring | Adjust overall brightness in the midtones. To reset, press F4.
   Second jog ball | Adjust brightness in the midtones for a range of colours. To reset, press F5.
   Third ring | Adjust overall brightness in the highlights. To reset, press F7.
   Third jog ball | Adjust brightness in the highlights for a range of colours. To reset, press F8.
   F9 button | Toggle between the panel default and alternate setup.

Grading in Logarithmic Mode Using the Function Panel

When the Grade menu is enabled, you can use the Function panel to:

- Adjust overall hue, brightness, and saturation.
- Balance brightness and contrast in the red, green, and blue channels.
- Balance brightness of colours in the shadows, midtones, and highlights.
- Adjust cutoff values.
- Increase or decrease printer light settings.

To colour grade in Logarithmic mode using the Function panel:

1. Press the Grade button on the Navigation panel.

   The In Primary, Out Primary, Inside, and Outside options are activated.

2. Do one of the following:
   - Press the F1 option button to work on the initial primary grade.
   - Press the F2 option button to work on final curve modifications.
   - If you are colour grading a secondary, either a key or a geometry, use the numeric keys on the Navigation panel to select and activate a secondary layer. See Adding Secondary Layers.
3. If you are accessing the Grade menu after having created a geometry or key, do one of the following:
   - Press the IN option button to grade inside the secondary.
   - Press the OUT option button to grade outside the secondary.
4. On the Function panel, use the following controls.

   Use: | To:
   --- | ---
   Wheels | Modify overall hue, brightness/contrast, and saturation. Wheel 1=Hue Wheel 3=Brightness/contrast Wheel 4=Saturation To reset a wheel, press the button above it.
   Knobs at top left | Balance brightness or contrast in the RGB channels. Knob 1=Red brightness/contrast Knob 2=Green brightness/contrast Knob 3=Blue brightness/contrast To toggle knob functionality, press the F1 button in the centre column. To reset a channel, press the button below it.
   Knobs at top right | Balance S/M/H brightness of the colours, or adjust cutoff values. Knob 4=Brightness in shadows/cutoff values Knob 5=Brightness in midtones/cutoff values Knob 6=Brightness in highlights To toggle knob functionality, press the F4 button in the centre column. To reset a knob, press the button below it.
   First row of buttons at bottom right | Increase printer light values. F1=Red F3=Blue F5=Green F7=Overall
   Second row of buttons at bottom right | Decrease printer light values. F2=Red F4=Blue F6=Green F8=Overall Press ALT for half point adjustments.
   SHOW button | Toggle the geometry wireframe on or off.