Zenphoto does that if it can. To cite from our user guide:
Quote:Ideally, permissions should be set up with 0644 files/0755 directories ([rw-r--r--] files and [rwxr-xr-x] directories) permissions, with [youruser:webservergroup] ownership. If you can do that, we highly recommend it. The idea is basically to keep ownership of the files yourself, give group access to the web server, and shut everyone else out.
http://www.zenphoto.org/news/permissions-for-zenphoto-files-and-folders
That it does not happen on your server means that something with the user/owner settings is not correct. It generally does work even on standard shared hosts where I generally use ZP.