OK I'm getting closer....
/usr/local/bin/gphoto2: /usr/local/bin/gphoto2: cannot execute binary file
Using command within CGI as follows:
system("sudo -i -u www-data gphoto2 --set-config capture=on --set-config capturetarget=1 --set-config capture=on --set-config eos-shutterspeed=".$code." --set-config capture=on --set-config eos-iso=".$icode." --set-config capture=off --capture-image");
Any idea's what I've done wrong now....