Seán Duggan: Working Smart with Smart Previews in LR5, Part 1
Jun 2013 27

One of the new features in Lightroom 5 that is sure to be welcomed by many people, especially those who work with laptops, is the addition of Smart Previews. This new way of managing preview images will go a long way towards ending the frustration of the dreaded question mark icons that used to appear on image thumbnails if Lightroom couldn’t locate the actual source files.

A Smart Preview is a lossy Digital Negative File (DNG) that is saved at a smaller pixel dimension than the original. For images where Smart Previews are present, most of Lightroom’s features and functionality are available to you, even if the hard drive containing the actual image files is not connected to your computer. For the photographer who travels a lot, this is a huge improvement.

Creating Smart Previews

Smart Previews can be created upon import by clicking the “Build Smart Previews” check box in the File Handling section in the left hand panel on the Import dialog

For images that are already in your catalog, you can select them in the Library module and choose Library > Previews > Build Smart Previews. In that same menu there is also a choice for discarding Smart Previews. This can be useful if you no longer need to have Smart Previews for a group of images and you want to reduce the file size of your Lightroom catalog (more on that aspect of Smart Previews will be covered in Part 2 of this article).

Working with Smart Previews

When a Smart Preview is present for an image you’ll see a status line under the Histogram for the selected image that indicates this. When the original image can be accessed by Lightroom it will read “Original + Smart Preview”. Click on this to prompt a dialog that will allow you to discard the Smart Preview for the selected file.

If Lightroom cannot access the original and is working with a Smart Preview, the status will simply read “Smart Preview”. When a Smart Preview is available for an image, you’ll see a small white rectangle in the upper right corner of the image thumbnail (the same place where the question marks were when an image was missing in previous versions of the program).

And if there is no Smart Preview associated with the file and the original cannot be accessed, it will inform you that the “Photo is missing”. When a photo is missing there is no histogram display and all of the Develop module controls are greyed out and unavailable.

For missing photos with no Smart Previews, a small exclamation mark icon appears in the upper right corner of the image thumbnail. Clicking on this, or on the “Photo is missing” status under the histogram, will bring up a dialog to assist in locating the actual file.

What You Can Do with Smart Previews

Smart Previews are 2540 pixels on the long edge (with images that are a standard 3:2 aspect ratio, this is approximately a 4.3 megapixel image) and this size, as well as the ability to support Raw image data in the DNG file, means you can take advantage of most of Lightroom’s features and functionality, even if you are not connected to the hard drive where the actual image files live. This includes all of the possible adjustments you could make in the Develop module. It is recommended, however, that you save Sharpening and Noise Reduction for working on full-size originals. You can also export files, make slide shows and web galleries, and even create or refine a book layout (ordering the book needs to wait until you are connected to the actual files).

Printing images from Lightroom will require that you are connected to the drive containing the actual files. You can set up the print layout and save that layout for later use by clicking “Create Saved Print” in the upper right above the layout preview, but pressing the Print button will prompt a message informing you that the source file is missing. In terms of exporting files, a width or height of 2540 pixels is enough to make a high quality 8×10 print. While you may not be able to make large exhibition or portfolio prints, Smart Previews do give you the ability to export files for screen display and small to moderate sized prints.

Better Living Through Smart Preview Technology

Smart Previews represent a significant improvement to the Lightroom workflow and they will allow photographers more freedom in terms of when and how they can work on their images, especially when they are away from home or the studio. In Part 2 of this article, I’ll examine how Smart Previews impact the size of your Lightroom catalog and take a look at considerations for how to use them so that they can enhance your Lightroom work without causing cataog file size concerns.

Seán Duggan is a fine art photographer and the co-author of Photoshop Masking & Compositing, Real World Digital Photography, and The Creative Digital Darkroom. He leads workshops on digital photography, Photoshop and Lightroom.