I'm looking for an option to have two instances of the same image/file next to each other (dual view), so that I can edit one of them and see the difference between the original file and the edited one. However, I can't find it, not by looking around my self nor by Googling for it.
There is one dual-view option (
Window > Arrange > New window for <filename>), but any changes applied are applied to both, so this isn't what I'm looking for.
I doubt such an important function wouldn't be part of Adobe Photoshop... Does it exist or not? How can I find it?
The only way to achieve what I want right now, or at least as far as I can think of, is to make a copy of the original file and open it next to the file I'm going to edit.