Digital entries should be in jpeg format dimensioned so that the width does not exceed 1,400 pixels and the height does not exceed 1,280 pixels.
Click here for a document on how to downsize to fit these dimensions (best to download the document to your desktop before reading!).
The filename is not important for images entered through the S4C online entry system. The system assigns its own filenames. Filesize is also unimportant, It is recommended that the jpeg quality be set to its maximum.