Quite often, there will be something important in the image that's either too dark or too light, and you need to bring it out.

In the case of this sample picture, we'd like to bring up the tones on the two principles' faces, and bring down the brightness of the sky behind, to try to pull out a bit more detail from the clouds.

First step: the faces. Select the Dodge tool from the tool palette. The dodge tool shares a bin with the burn tool and the sponge tool. To change them, click and hold down on the tool until the small tool selection list comes up, then choose the tool you want to use.)

Once we've selected the tool, the info bar below the menu bar will show what size and kind of dodge tool you're using. When you mouse over the document you'll see the size of the 'brush' you'll be using. For the least conspicuous adjustments, it's best to use a soft-edged brush, and adjust the size according to the area we're dodging-this is adjusted using the 'master diameter' slider in that window.

Since we're mostly going to be working with areas that are middle tones, select the 'midtones' option from the selector, and make sure the 'exposure' is pretty slight-most rarely use an exposure over 5% for photo adjustments.

With the dodge tool selected and adjusted for size and exposure, we'll have a whack at the image, clicking and holding over the parts of the image you want to affect, moving the cursor like one would an airbrush. A long click-drag-swirl around a face will work the same as several passes-use whichever method works best for you. It''s easiest to alter just a little at a time, so that we're never more than one UNDO away from something we know we liked.

If you get past the Undo point and need to return your image to an earlier state, consult your user's manual to learn about Photoshop's History feature.

Now for the sky. Choose the Burn tool from the Tools paletteand adjust the size of the 'brush' and the exposure to suit the job. It is mostly highlights and some midtones we want to change, so we'll start with highlights, and an exposure, again, of 5%.

Now that we've brought some of the highs and mids down in the sky, the whole picture looks better. But now we see some junk in the sky we didn't see before, over the guy's head-looks like noise from the scanner, not clouds, and we want to be rid of it...

Choose the Cloning Stamp tool from the tool palette, and set a size for it like you did for the dodge and burn tools. Again, it's generally best to use the soft-edged brushes; they make for less conspicuous edits.

When spotting a small area, you may find it useful to zoom in to see more detail. Select the Magnifying Glass tool and click on the area of the image you wish to magnify. To zoom back out, hold down the Option key, which will give you a 'demagnifying glass' cursor, and click until the image is original sized. Note: Most menu operations can also be accessed with keyboard shortcuts. For example, to zoom in, hold down the Command key and Spacebar together (the cursor will turn into a magnifier), then click on the image with the cursor. Zoom back out with Cmd-Opt-Spacebar).

Another very handy timesaver is the spacebar. Any time your image is magnified, you can navigate around within the window by holding the spacebar, which turns your cursor into a little hand. Use the hand tool to drag your way around the magnified image. Wonderful stuff!

Users can zoom in, zoom out, and move around the image while using most (if not all) of Photoshop's tools-this allows much finer control over critical operations.

The Cloning stamp works by taking pixels from some location you select and cloning them into the areas you apply the stamp brush. If possible, find an area that has identical tone and texture to the area of your image you want to clone out spots.

In this case, the sky around the spots is real close, so we'll mouse over that area, hold down the Option key (the cursor becomes a crosshair), and click. This tool can take some getting used to, but it's amazingly powerful.

Generally it's best to have the opacity set at 100% usually, and the 'aligned' box checked-see these settings in the Tool Options bar.

If it's not clear exactly what these settings mean, a few moments of experimentation will be an easier lesson than an explanation.

Now that you have your sampling area selected, click (don't Option-click, just click) on the offending spots and see what happens. Remember, one click, one undo...

If you've selected well, you will completely remove the dust specks; if you haven't you might find an extra eyeball floating in the sky.