Chapter 7. Size and Sharpen Photos

Digital photos have to be sized for specific uses. They are not like using film. With film, you simply put the negative into an enlarger and make the picture bigger or smaller as needed — the original image never changes. You cannot do that with a digital photo. Once a picture is resized to a small image, for example, that resulting small image file cannot be resized with any quality to a big picture.

In general, do all of your processing work on a photograph using a master Photoshop or PSD file, and then save that master file for any future resizing purposes. The best way to do this is to create a new file for every new size of picture that you need. You do not want to resize your master file and then save over that because you will not be able to get back to the original size from that saved file.