Continuing the short primer on the Retouching Tools. The Eraser and Paint bucket tools.
Most people will most likely have used these two tools in some way already, but it is worth just looking at the options on them:
The basic Eraser Tool is fairly straightforward. Just select the tools then choose the size and shape of brush and other characteristics you need from the Options toolbar
The Background Erase and Magic Eraser are slightly different:
Download this image to practice on, either by using this link, or by clicking on the thumbnail image right.
Background eraser is pretty simple to use, but it's effectiveness depends on the nature of the image.
The image left is a simple one for it to handle. select the tool and choose a brush size (25 - 30 pixels) then just click and 'paint' away the background. It is removed, leaving a 'null' pixel area.
Tip: use the 'Find Edges' mode to trace round a shape (such as this head and shoulders).
Magic Eraser is simple to use too and is a sort of partner to the Magic Wand Tool. According to the tolerance setting, it will try to erase pixels of a similar vaue to remove it in a similar fashion to the Background Eraser. As with the Magic Wand tool, it's success depends on the suitability of the original image.
The Paint Bucket tool is again a simple one to use, just click on an image to fill it with pixels of the current Foreground colour.
The Gradient Tool is a little more complex and is generally used for graphic effect. It will fill an area with a graduated fill of two (or more colours, beginning with the current Foreground colour and ending with the current Background colour.
Fills are determined by the angle you draw them (see arrow in screen grab left) and what type of fill you choose from the Options toolbar.