Import as DNG?


Today’s Question: Do you import [into Lightroom Classic] as DNG? Some photographers recommend saving RAW files in a separate folder on the hard drive and then importing as DNG into Lightroom. I’d like to know your thoughts.

Tim’s Quick Answer: No, I do not convert my raw captures to the Adobe DNG format during import into Lightroom Classic. I prefer to retain the original raw captures, for a variety of reasons.

More Detail: I have certainly heard many photographers recommend converting proprietary raw captures to the Adobe DNG format, but I do not generally recommend this approach.

Part of the reason I prefer to retain the original raw capture format is that I prefer to preserve the original capture just as it came out of the camera. In some cases, for example, there are proprietary details included with the raw capture that you would not be able to take advantage of if you converted the capture to the Adobe DNG format.

As I’ve mentioned in previous editions of the Ask Tim Grey eNewsletter, I also prefer to have my metadata updates stored separate from the original capture. When you save metadata to the source image in Lightroom Classic, that metadata is stored in a different location depending on whether you’re working with a proprietary raw capture or an Adobe DNG file.

For proprietary raw captures, metadata updates will be stored in an XMP “sidecar” file saved alongside the raw capture. For DNG images, that metadata updates will be saved directly within the DNG file. While saving metadata directly in the source image can certainly be convenient, it can also cause incremental backups of your photos to take more time.

To be fair, the Adobe DNG file format employs lossless compression that will cause no loss of pixel detail for your photos, and that can help reduce file size by around 20%. In theory, the fact that there is open documentation for the Adobe DNG file format means there is less reason to worry about a lack of future support for DNG images compared to proprietary raw captures. In reality, I don’t consider this a legitimate concern, especially considering that most raw-processing software applications today employed reverse-engineering to provide support for proprietary formats.

So, on balance, I prefer to retain my original raw captures. And as long as I’m going to do that, I don’t see a reason to save those raw captures in one place, and then convert to Adobe DNG for purposes of a Lightroom-based workflow.