Today’s Question: After opening a raw image in Photoshop I choose Layer > Duplicate Layer from the menu. I have been doing this routinely thinking it helped to preserve the original image. Is there any value to doing this?
Tim’s Quick Answer: In my view it is not necessary to create a copy of the Background image layer in Photoshop unless and until you need to perform work that requires such a layer. Creating a copy of the Background copy will double the base file size of the image, possibly without a real benefit depending on your workflow.
More Detail: I am an advocate for a non-destructive workflow in Photoshop (or any image-processing software). That can translate into a variety of different things, depending on the task being performed in Photoshop.
For adjustments, I recommend using an adjustment layer unless the type of adjustment you want to apply isn’t available as an adjustment layer (such a with the Shadows/Highlights adjustment). For image cleanup I recommend applying the cleanup on a new empty image layer, unless the cleanup tool you’re using (such as the Patch tool) doesn’t enable you to work across multiple layers to place the cleanup pixels onto an empty image layer.
In situations where it isn’t possible to apply the intended effect with an adjustment layer or work on an empty image layer, then you’ll generally need to make a copy of the Background image layer (or another layer such as with a composite image). In those cases, I certainly wouldn’t hesitate to create a copy of the full layer.
However, duplicating a layer also increases file size. For an image that only consists of a Background image layer, duplicating that layer doubles the size of the file on your hard drive. So, in general I don’t recommend duplicating a layer unless doing so is necessary. This requires, of course, that you use a layer-based non-destructive workflow, and that you are careful to make sure you have the correct layer selected at all times on the Layers panel.