Create ISO From CD/DVD in Mac OS Without Using External Application

Step by step for creating ISO (.iso) file from CD/DVD in Mac OSX (Here I'm using OSX 10.8.3).

1. Insert the CD/DVD
2. Open Disk Utility (in launchpad : Other -> Disk Utility)
   
3. Select the CD/DVD and press "New Image"
4. Select a folder to save the file and select CD/DVD Master in "Image Format", press Save, and the creation of image file will start
5. Open the folder and rename the file extension from ".cdr" to ".iso"
6. Test it by open the file ("open with" -> "Disk Image Mounter")