Smart Previews are designed to let you remove original files and work offline with all processing available. They also have the benefit of being loaded before the original file in Develop so you can get to work immediatelly.>
So how does it work? Well Smart Previews are Lossy DNG files sized to a long edge of 2540 pixels. Going larger than this takes up more room, but it would allow up to A4 printing with offline files at 3000px, but at least doubling the space used.
You can view the Smart Preview files- they live in the ‘Catalogname Smart Previews.lrdata’ file/folder, where Catalogname is the name of your catalog. Mac users will have to right click and ‘Show Package Contents’ to get into this package folder. Even though you can view them, don’t go messing with them!
When the original file is offline, you can work away with the Smart Preview. You can zoom to 1:1 at the orignal file size, but you get a pixelated view based on the 2048 limit of the Smart Preview.
So right now Smart Previews are good for offline editing and speeding Develop. The potential for the future is great. Think about integrating with Adobe Revel (or any other online service) where you have access to your whole Library online, and can edit, process and send any file at any time. This proxy workflow could be an absolute game changer for photography in the cloud. I’ll do a quick dropbox test shortly too. Is anyone else excited about this?