At the bottom right of the Viewer there is a dropper icon. By activating this option and placing the mouse over the Viewer, you’ll notice that a floating window is attached to the cursor.
This box provides information about the pixel just below the tip of the cursor:
- In the upper left and right corners, the cursor position is separated into two values, "X" and "Y" in the composition space which is based on its coordinate system.
- There is a dividing line next to the letter "B", indicating that the values displayed in this box are taken from input B
- Working Space RGBA: shows the values of the targeted pixel in Autograph’s linear space, used for all calculations
- Display Space RGBA: shows the values of the targeted pixel in the "Display Space", specified at the top of the Viewer
- Display Space HSVL: shows the Hue, Saturation, Value, and Lightness in the "DisplaySpace"
Remember that the Hue is described with an angle value between 0 and 359 degrees. For more information about the difference between Value and Lightness, please refer to the Wikipedia page about this topic:
Variations of RGBA values between 0.0 and 1.0 are visible in the Viewer, but it is quite possible for pixels to contain values higher than 1.0 (in the case of HDR images for example), or negative values (if you inspect a Position Pass from a 3D renderer for example).
Since your screen cannot display pixels brighter than white or darker than absolute black, the Viewer will visually display negative values as black and those above 1.0 as white. Keep in mind however, that this clamp is only visual and that Autograph preserves all pixel attributes, whatever their values, thanks to its calculations which are performed on 32 bits per channel (Float).
The Color Picker allows you to get information about the real pixel values where your screen is not able to reproduce the full dynamic range of your project. In order to temporarily compress the dynamics of your images into visible values, use the Post-Process of the Viewer, or add some color Modifiers, such as Grade or Color Curves.