Macros are too difficult, particularly when binary data streams are involved.
Another problem with pictures stored in databases and linked form controls is that the whole application becomes unusable as the amount of loaded pictures grows. As far as I know, all data of the form's record set are held in memory.
It is possible to bind a picture control to a text field. The picture control will show the picture of the file addressed by the relative URL stored in the text field. This seems to work smoothly with my private photo collection.
If some tool associated to your web-cam can automatically save picture files to disk then it should be easy enough to combine a shell script with the Base component.
The script generates a 2-column text table with the file dates and names of the picture files, the text file can be bound to a database table, the database table to the form (ordered descending by file time), and the picture control can be bound to the file name column.
My picture_links.zip contains a database document with an embedded HSQLDB and a form bundled with a set of picture files and a text file.
The text file has been created with a simple bash command:
ls -1 *.{jpg,jpeg,png,gif} > pics.txt
which dumps a one-column list of picture files into a file pics.txt
This file is bound to a database column and the form's picture control is bound to that column.