I don’t know if Toast Light will do it. When you open the main window, right above the big red “burn” button in the lower corner is where you’d usually set the destination media in Toast. Options are CD, DVD and DVD DL.
To create a disc-image, I’d personally use Toast with its “Save as Disc Image” feature. The other way I know is to go to the Utilities in Mac OS and open up Disk Utility. There’s a “New Image” button on the top bar. When you click that, you can set the parameters for your disc image, such as size (with a DVD DL preset available) and permission. I think you’d want “read/write” and not a sparseimage. Once the image is created, the OS opens it as if it were a connected device. You can put what you want in it and eject it. The .img file you created in Disk Utility should now contain what you put in the container. You can then move around the img file with all its contents. Super-useful. You can keep adding stuff until you reach your image’s maximum size. The img file can be burned in most burning software.
IHTH
JC Boulay
Audio Z
Montreal, Canada
http://www.audioz.com