In general, storage capacity depends on which image size and quality you have selected.
For your information, here is number of full size images (2560x1920) that can be stored in a 16MB Compact Flash in the respective image quality mode. Since the image size may vary depending on scenes and subjects, these are approximate values only.
• Economy: 20
• Standard: 12
• Fine: 6
• Super Fine: 1
• RAW: 1
For more details, please see the instruction manual.