### The main toolbar

The main toolbar allows you to perform several common operations common to the display of the image and bring up other image windows. It consists, from left to right, of:
The W icon stands for Windows and clicking on it will list all possible windows that can be created. Currently, these include:

- The Image Information Window
- The Reel List Window
- The Color Area Window
- The EDL Edit Window
- The Network Connection Window
- The Hotkeys Window
- The 3d View Window
- The Histogram Window
- The Vectorscope Window
- The Waveform Window
- The Preferences Window
- The About Window

The Channel display tells you what channel you are currently viewing (Color in the above picture).
The usual channels can be one of R,G,B,A and Lumma or Alpha Overlayed on top of RGB.
However, for image formats that support it like OpenEXR or Photoshop's PSD, it can also list all layers that are in the image.
The Gain control allows you to change the display gain of the image being displayed.
You can use CTRL+LMB to change it interactively.
The Input Color Space control displays the OCIO input color space for the image. It defaults to scene_linear, but the default can be set in the Preferences->OCIO (and the image depth). This setting works in tandem with the Gamma and Lut buttons.
When CTL is on, this setting does not appear. Instead, the F-Stop and the Normalization settings will show up.
The F-Stop control is another way to control gain. It works in F-Stops, which is a common method used in photography and film to adjust a camera exposure.
When OCIO is active, this requester is not seen by default, but it can be displayed if you press SHIFT+i (default hotkey).
The Normalization button allows you to normalize the image within the 0 and 1 range. Its most common use is for properly viewing Z-Depth channels or shadow maps.
When OCIO is active, this requester is not seen by default, but it can be displayed if you press SHIFT+i (default hotkey).
The Gamma control allows you to modify the display gamma. The gamma pulldown allows you to select several common gamma settings.
When OCIO is active, instead, the pulldown allows you to select the Display/View of OCIO for the monitor.
The Field control allows you to display the image as a full frame or as video fields.
The 1:1 button allows you to toggle on and off a compensation for an image's pixel ratio.
By default it is off, which means that the pixel ratio is not taken into account.
The LUT button allows you to toggle the 3D LUT color correction for emulation of other media on your monitor.
This buttons toggles OCIO on/off and CTL on/off.
The main toolbar can be toggled on and off by using the F1 hotkey.