Dual screen for comparison in Photoshop CS6
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.
Duplicate the existing file, in its current state. Use the original as your preview of new ideas and future changes. Use the the duplicate as the version to compare things back to.
There's also a layer mode change state thing in Photoshop CC, but it's not stable, doesn't account for all changes and isn't kind on memory, so I don't recommend it.
The manual approach of duplicating files is safer, faster, better.