Today’s Question: You said [in yesterday’s Ask Tim Grey eNewsletter] that you could improve performance by preferring the use of Smart Previews in Lightroom. What does that mean and how do you enable it?
Tim’s Quick Answer: You can improve (often significantly) the performance of Lightroom when optimizing photos in the Develop module by using Smart Previews (rather then the source images) as the basis of those adjustments. To enable this option turn on the “Use Smart Previews instead of Originals for image editing” checkbox on the Performance tab of the Preferences dialog in Lightroom.
More Detail: The Develop module in Lightroom makes use of the original image file as the basis of the adjustments you apply. That helps ensure you see the most accurate previews possible, but can also result in degraded performance. It is possible, however, to use Smart Previews as the basis of your adjustments in the Develop module, which will generally improve performance (sometimes quite significantly).
The first step is to generate Smart Previews for all images you want to work with in this way. You could, for example, select all images in your entire Lightroom catalog and then choose Library > Previews > Build Smart Previews from the menu to generate Smart Previews for those images. You can also build Smart Previews as part of the import process by turning on the “Build Smart Previews” checkbox in the Import dialog.
With Smart Previews built for your images, you could simply make the source images unavailable to automatically make use of the Smart Previews. For example, if the source images are on an external hard drive you could disconnect that hard drive from the computer. Lightroom will then use the Smart Previews in the place of the source images when you work in the Develop module.
In addition, you can prioritize the use of Smart Previews in the Develop module even when the source image files are available, in order to improve performance. You can enable this option in the Preferences dialog, which you can bring up by choosing Preferences from the Lightroom menu on the Macintosh version or from the Edit menu on the Windows version. On the Performance tab you can then turn on the “Use Smart Previews instead of Originals for image editing” checkbox. Lightroom will then use the Smart Preview (if available) within the Develop module, even if the source image is currently available. Note that the preview may not be as accurate, but performance will be improved.