Today’s Question: Does your recommendation to only use “Save” (not “Save As”) for images sent from Lightroom to Photoshop apply even if you want to keep the Photoshop-modified file as a separate version?
Tim’s Quick Answer: Yes. When you send a photo from Lightroom to Photoshop, you are already creating a derivative image file. Therefore, you don’t need to use the “Save As” command to create a new file. Lightroom will have already created that new file for you.
More Detail: When you send a RAW capture to Photoshop from Lightroom, a new image file will be created for you automatically. In the Preferences dialog you can go to the External Editing tab and choose whether you want that new file to be a Photoshop PSD file or a TIFF file, by choosing the preferred option from the “File Format” popup.
The fact that this image file is being created for you as part of this process is the reason you don’t need to use the “Save As” command in Photoshop. In effect, Photoshop already knows where to save the file and what the filename should be, because the file was already created by Lightroom and is simply being opened by Photoshop.
If you are working with a non-RAW capture, Lightroom will give you the choice of creating a new copy of the image, or opening the “original” version of the selected file. By choosing to create a new copy, you will likewise have a derivative image, and can still use the “Save” rather than “Save As” command in Photoshop.
The bottom line is that when you are using Lightroom to manage your photos, you want to initiate all tasks from within Lightroom. If you want an additional version of a photo that will be worked on in Photoshop, the creation of that additional version should be initiated in Lightroom.