Rich,
You say it is a small image being scanned. Can you tell us the exact scan angle that you are operating at with the FB3? What might be ILDA standard might look 'small'
Also I am sure you have tried adjusting the scan settings in the software? What software are you using with the FB3? When I use the FB3 software I can get HUGE projection zones compared to when I use the LA Freak software.
-Max