Month: September 2015

Today’s Question: This is a follow up to a question from last week [about merging catalogs in Lightroom]. I have two catalogs that I want to merge into one. Unfortunately, I have several photos that exist in both catalogs. Is there a way when merging two catalogs for Lightroom to alert you if a photo already exists in the catalog you are merging into?

Tim’s Quick Answer: When you merge catalogs via the “Import from Another Catalog” command in Lightroom, you will have the option to choose how to deal with any duplicate images. You can’t actually create duplicate copies in this case, and instead can choose whether you want to replace information in the destination catalog with information in the source catalog for the duplicate photos.

More Detail: If Lightroom detects that any of the photos from the source catalog are already contained within the destination catalog (your “master” catalog), you will see a notification indicating how many duplicate images were found within the “Import from Catalog” dialog.

If you know that the images in the destination catalog are your true “master” versions of all photos, you can simply choose the “Nothing” option from the Replace popup, and the duplicate images will be skipped in terms of the catalog merging process.

If the images from the source catalog are the more recent versions of your photos, you can choose to replace information in the destination catalog based on the information in the source catalog. You can choose whether you want to only update metadata (including Develop adjustments), or if you want to replace the original image files as well. In most cases, of course, the two source files would probably be identical, and so you could choose the “Metadata and develop settings only” option from the Replace popup.

If you’re not entirely sure which version of the duplicate photos is really the latest (or best) version of the photo, you can also turn on a checkbox that will create a virtual copy based on the second version of the duplicate images. That checkbox is labeled “Preserve old settings as a virtual copy”.

In addition, if you have a mix of RAW and non-RAW (such as TIFF and JPEG) images, you can choose whether you want to replace non-RAW captures only, updating only the metadata for RAW captures. That checkbox is labeled “Replace non-raw files only (TIFF, PSD, JPEG, PNG)”.

These options in the “Import from Catalog” dialog enable you to choose how to deal with duplicate images when merging catalogs into a single master catalog. The result will be a single copy of each image (or an image plus a virtual copy), so that you don’t have duplicate photos in your master catalog (at least based on the merging of catalogs).

Today’s Question: I know you don’t convert to DNG on import in your workflow, but for those of us that do I wonder if there are any advantages or disadvantages of also converting JPEG files (as from my phone) as well as RAW files?

Tim’s Quick Answer: I would say there aren’t any real advantages to converting a JPEG capture to the Adobe DNG file format, and there is certainly a disadvantage in the way of a file size that would be at least slightly larger for DNG as compared to the original JPEG.

More Detail: It would be reasonable to assume that converting a JPEG image to the DNG format would open up the possibility of applying “better” adjustments via Lightroom or Adobe Camera Raw, but that would not be an accurate assumption. You can already apply adjustments to JPEG images in Lightroom or Adobe Camera Raw, and there is no real benefit to converting a JPEG to DNG first.

In theory you might gain a slight advantage in terms of enabling a high-bit workflow and avoiding additional loss of quality and detail due to file compression. But in reality you are already starting with low-bit data, and with an appropriate workflow you don’t need to be worried with quality loss. Within Lightroom, for example, applying multiple adjustments in multiple stages does not have a cumulative negative impact on image quality.

While the DNG file format does employ lossless compression when converting RAW captures, yielding a DNG file that is generally around 20% smaller than the original RAW capture file, that does not hold true for JPEG images. Instead you will generally find that the DNG file is about the same size or possibly slightly larger depending on the settings for the original JPEG image.

So, on balance I would say there is no reason to convert JPEG images to the DNG file format. There are certainly reasons to consider DNG as a “replacement” file format for your original RAW captures (though as you note I am not a proponent of this approach), but not for JPEG images.