How does Aperture apply changes to image files nondestructively?
2.
How does the Straighten tool work?
3.
Name two types of automatic adjustments in Aperture and explain how to make them.
4.
What is a histogram and what kind of information does it show in Aperture?
Answers
1.
When you make adjustments to an image, Aperture creates a "version" of the master file that includes your adjustments and embedded information; Aperture leaves the master file untouched. Versions do not actually exist as independent image files. Adjustments to an image are kept as a set of instructions linked to the master image. When you view a version, Aperture uses the original master file as a resource and applies the linked set of instructions to the image on your display. In this way, all image adjustments made in Aperture are nondestructive.
2.
The Straighten tool allows you to straighten uneven images: for example, to make a horizon line level. As you drag with the tool, a grid appears to help you make the adjustment, and the image rotates around the crosshair in the middle of the image.
3.
Aperture allows you to automatically adjust the exposure and levels of images. You do so by selecting an image in the Browser so that it appears in the Viewer, and then click the Auto Exposure or Auto Levels button in the Adjustments Inspector.
4.
A histogram is a graph that plots the brightness values of an image from the blackest to the whitest. By looking a histogram, you can tell such things as where the pixels are concentrated in an image (in the shadows, midtones, or highlights), whether the overall tonal range is smooth, and whether the shadows or highlights are clipped. In Aperture you can view five types of information in the histogram: luminance, combined RGB channel data, and separate red, green, and blue channel information.
Keyboard Shortcuts
R
Select the Rotate tool
Command-Z
Undo last action
A
Select the Selection tool
[
Rotate the selected image(s) 90 degrees counterclockwise
