Source Photo for Derivative


Today’s Question: When taking a RAW file through post-processing, creating a master file (a TIFF or PSD), and then creating a derivative file from the master file for social media, etc., is it possible to trace the derivative file back to the original RAW file and/or master file? I ask because in organizing my Lightroom catalog, I came across a JPEG that looks like it was processed from one of my RAW files, but has no information in the EXIF data identifying where it originated from. My file renaming over the years has screwed-up any naming associations I could possibly make to help with identifying this JPEG’s origins, so no help there.

Tim’s Quick Answer: For an existing image, you can generally use metadata values (such as capture time) to help you locate the original photo that was used as the basis of a derivative image. In this case it sounds like that isn’t an option because the exported JPEG had some (or most) of the metadata excluded. That certainly makes it difficult to match up a derivative image with the source image. Moving forward you might consider retaining metadata in exported images, and grouping derivative images into a stack with the original source image.

More Detail: By default, when you send a photo from Lightroom to another application (such as Photoshop) the derivative image will have the same base filename as the source image, and will be saved in the same folder. This generally makes the task of locating the source image for a given derivative relatively easy.

If the derivative was moved to a different location and you have renamed that file so that it no longer matches the source image, the search for the source image can be a little more complicated.

As long as the metadata from the original image is included with the derivative image, that metadata can often be used to locate the original photo. For example, you could navigate to the “All Photographs” collection in the Catalog section of the left panel in the Library module, and then filter images based on the capture date of the derivative image. Sorting by capture time would then reveal the source and derivative images right next to each other.

In a similar way, you could use any other metadata that was somewhat unique to the image in question as the basis of a filter to help you locate the original. But if the metadata from the original image is not included in the derivative image, the use of metadata obviously won’t be helpful in your search.

Another option relates to stacking images together. By default, when you send a photo to Photoshop from Lightroom, the derivative image will be placed into a stack with the original. You can turn this option off in Preferences, but I recommend leaving it turned on so that you will have the original and the derivative grouped together in your Lightroom catalog. In addition, I prefer to retain the same base filename, and keep all derivatives in the same folder as the source image.