UNDERSTANDING FILE SIZE

Because Photoshop requires about five times the file size of an image to work comfortably, you may need to consider how many files you have open at the one time and what affects file size. Several factors can affect the size of an image, including its file format, its actual dimensions in pixels, the number of colours that are used in the image and its resolution.

Understanding File Format

When working on images in Photoshop, you will need to consider different file formats, based on what your images are and what you plan to do with them. For example, you may want to place your images on a website or email them, in which case they need to have a small file size so that they load quickly. This page describes four file formats and how and when they should be used.

Creating A New Image

There are various options that you can set as you create a new image in Photoshop. You can select the appropriate resolution, colour mode and background colour for the image. You can also specify either a custom size for your image or choose from one of the numerous preset sizes that were created by Photoshop.