Lightroom Smart Previews are compressed copies of the image files. They are saved as DNG files with the longest edge of 2540 pixels and are stored in a .lrdata file.
In the screenshot below you can see my folder with two files in it. The .lrcat file is the Catalog itself. And .lrdata file contains Smart Previews.
Smart Previews are very small. I exported the original Raw files (123 photos) with the total file size 3.5Gb. The Smart Previews folder was only 116Mb. The Smart Preview file is only a 3% the size of the Raw file and most of the time it’s less than 1 Mb.
During the editing process, I do not see the big difference between compressed and original files. They look as good as the original files, which allows to edit them on the laptop without connecting an external drive.
How to create Smart Previews
There are four different ways to generate Smart Previews.
1)With Export. To export all wedding or session photos as a Catalog, select all images (Command+A/Ctrl+A), then go to File > Export as Catalog and tick the Build / Include Smart Previews box. If you need to select several images from the session this method will work for you too. Just select the images using the Ctrl key.
I recommend my clients to use this method because I ask them to edit 20-30 images beforehand, so I could have anchor images within the catalog. Also, you can select the particular folder you want to save it and rename your catalog files.
2) Import window. Select “the Build Smart Previews” box in the File Handling panel.
3) Library. Select the images for which you want to create Smart Previews then go to Library > Previews > Build Smart Previews. (Note: It’s no longer an option for 8.2 version).
4) Develop module. Select mage and click on the Original Photo icon in the Histogram panel. This method will let you build a Smart Preview for only one photo at a time.
Speed up your Workflow with Smart Previews
Lightroom runs faster when editing Smart Previews compared to original files. If you take the time to build Smart Previews for your images and then disconnect your external drive, you’ll notice an increase in processing speed.
To make it work go to Lightroom > Preferences > Performance tab and tick the Use Smart Previews instead of Originals for image editing box. Then restart the Lightroom.
This will help you to work faster in the Develop module.
You need Lightroom CC 6.7 or newest versions to enable this feature. You can check which version you have by going to Lightroom > About Adobe Photoshop Lightroom (Mac) or Help > About Adobe Photoshop Lightroom (PC).
Lightroom Smart Previews are a very useful tool. It makes your work experience in Lightroom easier and faster. If you have any questions about Lightroom Smart Previews, please let me know in the comments.
I work with weddings photographers providing private photo editing services. If you want to read more information about my services, please, visit this page – Pricing page.