iso files w ISObuster...

[Homeric]

I don't well understand the way to create an *.iso file using Isobuster??
I left-click on the CD icon in the left part of the window's application, I select "Extract CD <image>" and then I select "RAW (*.bin *.iso)
but should I specify the extension while choosing the name file??? for exemple "backup.iso" or "backup.bin"... because there is no other way to specify the file extension!
Is ISObuster a good way for creating iso files?
Are there other programs?