Lightroom 5 added new Smart Previews. These let you work with images which are not found or on a disconnected drive, also known as Offline Editing. All Adobe documentation says that Lightroom Smart-Previews are good for working offline.

Now, if one never works offline, are Smart Previews still useful or advantageous in any way? I just did the 4.4 to 5.3 upgrade and the new previews are taking a huge amount of space.


2 Answers 2


Smart Previews surfaced for one primary reason: RAW file size.

Smart Previews are essentially small RAW files, re-sizing the RAW file down to a copy with 2048px max width. Keeping full sized RAW files on a server is impractical due to their large size, but there are other local advantages, too.

Each time you make an edit in LR, it has to "consult" the original RAW file and generate a new JPEG preview. If you keep your RAW files on a HDD, and your library on a SSD, it's spooling up that HDD each time you make an adjustment. This use of energy is increased if your RAW files are external, on a NAS, or in the cloud. This small size allows quicker updates as it "consults" the smaller RAW file, which, due to their smaller size, Adobe is hoping is more local.

This means that you have a good gain from using these files locally, even if you're always connected to your RAW files. More efficient preview updates means better performance. The only time this is not true, is if you keep your Lr library and RAW files in the same location. Lr will then consult the original RAW and you are wasting space with the Smart Previews.

This opened the gates for Adobe to take your RAW files into the cloud, put RAW files on tablets, etc. These are the benefits that Adobe is pushing since these are the benefits that bring in more $$ by selling subscription based Creative Cloud.

  • \$\begingroup\$ In my case, the images and library are on different disks. The images are on a read-only mounted SSD and the catalog is on a read-write one. They could not be on the same for those permissions but there is no penalty for accessing the originals, so I think it would fall into the same argument as the one in your third paragraph or did I miss something? \$\endgroup\$
    – Itai
    Apr 12, 2014 at 14:12
  • \$\begingroup\$ If they are on two drives with equal performance, I doubt there would be little, if any, advantage to smart previews. \$\endgroup\$
    – AndyML
    Apr 12, 2014 at 17:20

smart previews files are also driving the newly announced lightroom for mobile product, so if you ever plan on using that, you'll want to create smart previews as well.

I keep all but the files I'm actively working on stored on a network server, and smart previews means I can carry my laptop with me and use images as if they were on the laptop drive under most circumstances if I need to. Once you start moving around that comes in very handy.

  • \$\begingroup\$ Interesting but this answer brings out much more questions! I just got my first own laptop and so I've been wondering on how to integrate in my workflow. In your case, where is/are your catalog(s)? If they are more than one, how to do you keep them in sync? \$\endgroup\$
    – Itai
    Apr 12, 2014 at 14:08
  • \$\begingroup\$ this is something I'm actually working on a detailed writeup on ( chuqui.com/getting-geeky-lightroom ) , but quickly -- catalog on the laptop drive in the standard place. newly imported and work in progress on the laptop. stuff I'm done with on the network server. I keep the RAW files for the 4 and 5 star local as well. \$\endgroup\$
    – chuqui
    Apr 12, 2014 at 17:46
  • \$\begingroup\$ Does that mean you are always on the laptop? And therefore cannot browse your catalog from your desktop? It's kind of backwards from the way I'd like to work :( \$\endgroup\$
    – Itai
    Apr 12, 2014 at 23:55

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