Lesson 11 Quiz

Blending works by stacking the photographs on separate layers and painting a mask on the top one to hide the parts you do not want. Any editor with layers and masks can do it, whatever it is called, while presets, red-eye removal and print layouts do nothing for compositing.

An edit on its own layer sits above the original pixels without replacing them, so you can lower it, change it or delete it at any point. Working directly on the photograph bakes the change in, and undoing it later may no longer be possible.

A selection fences off part of the image, and any edit you apply then touches only the pixels inside it. That is how you darken a sky, recolor one object or blur a background while leaving the rest of the frame alone.

Feathering blends a selection's boundary by spreading the transition across a specified number of pixels. The result is a gradual fade rather than a hard cut, which makes composites and adjustments look natural rather than pasted.

A wide aperture throws the background out of focus, and blurring the background through a feathered selection imitates that while the subject stays sharp. The feathering hides the join; without it the subject looks cut out and pasted on.

These tools find an edge by looking for a change in tone or color between the subject and what is behind it. Where the two are similar there is little change to find, so the line wanders, while a sharp outline or strong contrast gives the tool a clear edge to follow.

Tolerance sets how different a pixel can be from the one you clicked and still be selected. A higher value takes in a wider range of tones and colors, which helps with an uneven sky but can spill into the subject if it is set too high.

Adjustment layers apply tonal or color changes through a mask that can be painted on or off, leaving the original pixel data untouched. This lets photographers experiment and revise without permanent consequences.

A warping tool moves pixels rather than changing their color or sharpness, so it reshapes contours and proportions, from a small fix to posture to a deliberate caricature. Used on people it changes how they look, so a light hand matters if the result is meant to pass as a photograph.

On a layer mask, black paint conceals the corresponding pixels on that layer, revealing whatever is below it. White reveals, black hides: this simple rule governs all mask-based compositing and selective editing.