Today’s Question: I am a Lightroom user and of course know that when I process a picture the changes are stored to be available in Lightroom, but a second file is not created. I need to understand using Adobe Camera Raw (ACR) from Photoshop CC. It seems that when I go to the ACR Filter and process an image, raw or not raw, it also stores the changes for later access in ACR. Is this true and can you provide some more details?
Tim’s Quick Answer: When you use Adobe Camera Raw to process a raw capture, the adjustment settings are indeed preserved with the image in an XMP “sidecar” file. Lightroom similarly preserves the adjustment settings you apply in the Develop module. When you use the Camera Raw Filter directly on an image in Photoshop, however, the actual adjustment settings are only preserved if you use that filter as a Smart Filter.
More Detail: Provided you’re using comparable versions of the two tools, you will find the exact same adjustments in Adobe Camera Raw and in Lightroom’s Develop module. Thus, you can achieve the exact same results when processing a raw capture by using either Lightroom or Adobe Camera Raw.
When you apply adjustments with either Lightroom or Camera Raw, the adjustment settings are preserved so you can revisit your adjustments later. In Lightroom those settings are saved in the catalog, but you can also save them to an XMP sidecar file by either choosing Metadata > Save Metadata to File from the menu, or by enabling the option to have Lightroom automatically save metadata (found in the Catalog Settings dialog).
The Camera Raw filter in Photoshop is a little different. This filter enables you to make use of the adjustments found in Camera Raw, but applied directly to pixel values within Photoshop rather than being used to process a raw capture. By default, as with other filters in Photoshop, the Camera Raw Filter will directly alter pixel values. However, you can also apply this filter as a Smart Filter to preserve greater flexibility in your workflow.
To employ a Smart Filter, first click on the thumbnail for the Background image layer on the Layers panel to select that layer. Then choose Filter > Convert for Smart Filters from the menu to convert the Background image layer to a Smart Object. Then choose Filter > Camera Raw Filter. The Camera Raw dialog will appear, where you can apply any adjustments you’d like. When you’re finished, click the OK button to apply the changes. Later, if you want to refine your adjustments, simply double-click on the “Camera Raw Filter” text below the Smart Filters layer on the Layers panel, in order to bring up the Camera Raw filter with your existing adjustments available for refinement.