Large DNG from Enhance Command


Today’s Question: I love the Enhance function to remove noise in Lightroom Classic. But the resulting DNG file is huge. Is there a way within Lightroom Classic to convert the DNG to a TIFF or high-resolution JPEG without a round trip to Photoshop?

Tim’s Quick Answer: You can indeed very easily create a derivative image based on the enhanced DNG image. Just keep in mind that if you save it as a TIFF the file will likely be even larger, and if you save it as a JPEG there could be issues with compression artifacts.

More Detail: The reason the Adobe DNG file created with the Enhance feature in Lightroom Classic, Lightroom, or Camera Raw, is considerably larger than a source raw capture is that the DNG will contain demosaiced capture data. In other words, rather than one color value for each pixel, it will have all three, causing the DNG file to be about three times larger than the source raw capture.

You could certainly create a TIFF copy of the DNG file, but it will likely be at least a little larger than the DNG, even with ZIP compression applied. You could also create a JPEG image file, but that would result in an image with only 8-bit per channel (which could lead to a loss of smooth gradations if strong adjustments are applied) and that could have some visible artifacts from the JPEG compression.

That said, you can certainly create a derivative copy of an image and add it back to the Lightroom Classic catalog without using Photoshop, using the Export feature.

To get started, select the DNG file and click the Export button at the bottom of the left panel in the Library module. In the Export dialog, set the Export To popup to “Same folder as original photo” and turn off the “Put in Subfolder” checkbox. Then turn on the “Add to This Catalog” checkbox.

You can then configure any of the other settings in the Export dialog based on the file type you want to create and the attributes for the image. Then click the Export button and a new image file will be created based on your specifications. The image will be stored in the same folder as the original and will be added to your Lightroom Classic catalog.