Depends on how big your average file sizes are.

For the average person, high-quality photographs will be 500-1MB, but can reach up to 5 or higher (depends on shot quality, etc.). Screenshots of video games (for example) are typically less than this. At 1MB per photo you could be looking at 8,000 images. Note that image compression options are available if you wish to store more - but you'll likely lose quality in doing this.