Open two copies of the same file side-by-side in Photoshop

In Photoshop, I can open two separate files and put them side-by-side to compare them. But can I do this with the same file? Can I open the same file in two different "tabs" in one Photoshop window, and put them side-by-side to compare them? I would be turning on/off layers in each instance.

Solution 1:

Looks like this feature does exist. It is called "New Window for". You can find it under:

Window > Arrange > New Window For [Image File Name]

Here is a tutorial: Dual View Photo Editing In Photoshop

And from the Adobe site: http://help.adobe.com/en_US/photoshop/cs/using/WSfd1234e1c4b69f30ea53e41001031ab64-74d5a.html

Solution 2:

Go to Window > History.

At the bottom right side of the panel, click on the first button that says "Create new document from current state", and you'll have a duplicate of your document.

Solution 3:

If you mean having a copy without messing the original file, go to Image → Duplicate.

Solution 4:

Yes you can, just open the file, go to File/Save As a Copy, and re-name the file. Once complete, open the copy next to the original. Voila.