Where is the name of the picture stored or come from?
What did you put into Field Expression?
What did you put into Pint When?
What are values stored in the "studnet.path" filed? Provide a few samples, please.

1:Not one picture More than 700. I store in a folder name"stpics"
2:I noting put into field expression.but the table and field name in "file" (get picture)
3:path(photo)
4:d:\school\stpics\001651.jpg
d:\school\stpics\001652.jpg
d:\school\stpics\001653.jpg