Operation Manual

3 Position the target area of the Loupe over the pixels in the image that are a neutral gray,
then click.
The white balance of the image is adjusted. The color tonality of the image is shifted
either cooler or warmer, depending on the tonality of the original image.
Important: Make sure that there is as little digital noise in the target area of the Loupe
as possible. Digital noise can skew the white-balance calculation results, introducing a
color cast that wasn’t previously there. A simple way to avoid errant pixels is to increase
the magnification of the Loupe by pressing Command–Shift–Plus Sign (+).
Adjusting Color Temperature with the Temp Controls
You can also adjust the color temperature of an image manually using the Temp parameter
controls. Color temperature is a term used to describe the color of light when the image
was shot. However, it refers to the color value of the light rather than its heat value. Light’s
color temperature is measured in units called kelvin (K). Adjusting the color temperature
of the image changes how Aperture interprets the colors in the image in relation to the
assigned temperature of light. The purpose of adjusting the color temperature of an
image is to make colors look as natural as possible.
To manually adjust the color temperature of an image
1 Select an image.
2 In the White Balance area of the Adjustments inspector or the Adjustments pane of the
Inspector HUD, adjust the Temp parameter by doing one of the following:
• Drag the Temp slider to the left to cool the tonality of the image, or drag it to the right
to warm the tonality.
• Click the left or right arrow in the Temp value slider to change the brightness of the
image by 10 K increments, or drag in the value field.
506 Chapter 17 Making Image Adjustments