2. Lightroom and File Formats, Pros & Cons

In general, it’s best to shoot photos in a RAW format, as it preserves the most information. Light Room was designed specifically to handle raw files. However, there is no standard RAW format, every camera and printer company have their own, which raises compatibility issues. You may not be able to edit your images in your favorite software until you either update the software or change the image format. Even if you can edit your images now, you have to worry about how things might change with new updates.

Since Adobe makes the premier editing software, you can save some headaches if you use their RAW format, called DNG (meaning “digital negative”). You can convert your images to DNG format as you import them in Light Room (it takes longer). There’s also a free DNG converter app available from Adobe. One advantage is that DNG files are about 20% smaller without losing any information. You also don’t need to create extra XMP files with them (to save a record of changes). The biggest disadvantage with DNG files is that they don’t always do well with 3^rd party plugins like TOPAZ or DXO which can remove digital noise and sharpen focus.

What’s an XMP File?

When you first use Light Room, you create an image catalog. All edits and labels added to images is saved in that catalog. If that catalog ever gets corrupted, you will lose ALL of your edits. You’d have to create an all-new catalog and do all those edits over again. To avoid this, you can create XMP files that save all the edits to individual images. Each XMP file pairs to one image. To create an XMP file click on Catalog Settings (for PCs, go to ‘Edit’, or click on Light Room Classic for Macs). Then click on Metadata. You’ll see a box for “Automatically write changes into XMP”. If you check that box, then every image you edit will create an XMP file for it. Then, if your catalog is ever corrupted, and you have to create a new catalog, as Light Room reads your RAW files, it will also read the XMP files and upload the pics with all your edits intact. Yay! Another advantage is, if you open an image with a separate XMP file in Adobe Bridge or Photoshop, it’ll show the image with those edits.

There aren’t many disadvantages to XMP files. It does double the number of files in a folder, but that’s no biggie. Then, although most XMP files are small, they can get up to 1-2 megabytes if you make a lot of changes to an image. Eventually, it can become a data storage issue. And then, if you have a slow computer, using XMPs might slow down the performance of working in Light Room, making it sluggish. It’s something to check when you first use Light Room.

Another thing to know. If you’ve already been using Light Room, and you don’t have XMP files, you can retroactively create them. Just select all your files in the left panel, then right click on them, select Metadata, and then “Save Metadata to Files”. When you do this Light Room will go through all your images and create XMPs for them.