Now you've got your image right-side-up, cropped, and looking clean and well-lighted, save it NOW.

NOTE: In the next step, we'll be reducing the resolution of the image file for the Web. If you wish to keep a high-res version, do a "Save As," rename the file you're working on, and perform the resolution changes on the new file.

Depending on the source of your digitized image, if you were to print this picture now, it might be tiny, the size of a 35mm negative, or the size of a wall poster, or anywhere in between. You probably need to size it. We'll assume it's only going to be used for the Web, so we'll adjust size and resolution to suit that use.

Under the Image menu, select Image Size.

The Image Size window will come up. By altering the settings in this window, you can size your image to be suitable for Web use. You certainly don't want people trying to look at an image barely an inch across, or trying to download a 30 megabyte high-res image over an analog modem!

As a starting point, let's say we want to size the image so that most folks can see the whole thing without scrolling around. The Web sees things in terms of pixels, not inches. Most folks' monitors will show an image 500 pixels tall by 700 pixels wide without scrolling.

This means that if you are working with a vertical-format image, it shouldn't have a Height dimension taller than 500 pixels. Likewise a horizontal (landscape) format image shouldn't have a Width of more than 700 pixels. The pixels/inch setting should always be set to 72 for Web work. It's generally helpful to set the pixels/inch setting first, and the dimensions second.

First set the resolution to 72 (making sure the units are pixels/inch). Then, ensure the Constrain Proportions box is checked-this will save you from doing the math to keep your picture from getting distorted). Now enter "500" in the Height box.

Note also the file size, next to Pixel Dimensions toward the top. It should say something like "400K (Was 34.6MB)." If you mistakenly choose too high a resolution, or choose a Height of 500 inches instead of 500 pixels, you can give the computer fits. Give all the parameters the once-over to be sure they are doing what you want them to, and click Okay.

Now your image is properly sized for Web use. To double check, hold down Shift and CTRL and click on the image. From the context menu, choose "Actual Pixels." Alternatively, look at the title bar of the image window, where the current magnification factor will be shown after the filename. If the magnification is anything but 100%, double-click the magnifying glass tool to display the image at 100%. You are now seeing it at the size it will render on a monitor running at the same resolution you're running at now.

Remember that when you work with the Image Size window, you are changing the image file itself. Once the resolution has been reduced, there is less visual information packed into the file. That is why it becomes smaller and more manageable for the web. The magnifying glass tool, on the other hand, does not actually affect the size of the file, it just allows you to get a closer look at details in your image.