The pictures you take are automatically assigned file numbers from 0001 to 9900 and stored in folders of 100 images each. Each folder on the CF card is numbered from 100 to 998. Automatic file numbering can be either by continuous numbering or auto reset numbering (the default setting is continuous numbering):

On the menu, select [File numbering]. Press the <MENU> button. Turn the <> dial to select [File numbering], then press <SET>. Select the file numbering method. Turn the <> dial to select [Continuous] or [Auto reset], then press <SET>. After the setting is completed, the menu will reappear. Press the <MENU> button to exit the menu and turn off the LCD monitor.

• If the 999CANON folder is created, [Folder number full] will appear on the LCD monitor. You can keep shooting up to file No. 9999, however, you should keep a spare CF card on hand.
• If file No. 9999 in folder No. 999 is created, "Full CF" will be displayed on the LCD panel and in the viewfinder and no more images can be recorded even if the CF card still has room. Replace the CF card with a new one.
• The file numbers are like the frame numbers on a roll of film.