Where is "Create disk image" function in El Capitan/Sierra? Updated today to Sierra from Yosemite. Can't find disk backup function in new Disk Utility...
In Disk Utility, you can use "New Image from Folder" accessible under File &gt; New Image &gt; Image from Folder or by Cmd ⌘Shift ⇧N.

Navigate to Computer or Volumes in the window and select your disk as the folder to create the image from. This should create an image of the disk.