The catalog has to be local.

Yes, but it also replicates the previews.lrdata. Have you enough space on Dropbox?

50Gb isn't many flash cards? Also the previews.lrdata can be big and a lot of files can change, so you'd also need the bandwidth. But assuming that's all OK, when you want to leave city A and close LR, you would then have to leave that computer on so  the local catalogue and previews can sync up to the cloud. And in city B, you'd have to wait for the  sync down to the local machine. Otherwise there's a risk that in city B you'd open LR and be working on an older version of the catalogue. It can be done, if you're careful and increase your backup, though it might be easier just to carry a big portable hard drive.

They've always been separate and I agree he doesn't have to sync them - but it will happen automatically and impact his Dropbox space and bandwidth. Maybe there's a way to tell Dropbox to ignore them?

Is that a paid option, Cornelia? I'm assuming that the OP will simply leave the lrcat on Dropbox, never copying or moving it.

I thought I'd heard there was a new option to point Dropbox to any folder. That said, I couldn't find it. So you're simply copying/moving the catalogue onto Dropbox, which would work - and isn't much effort.

If I read Victoria Bampton correctly in her new LR4-missing FAQs, you need to create a symbolic link inside the dropbox folder to tell the LR catalog where the previews are... (see page 335).

They've always been separate and I agree he doesn't have to sync them

Yes, the previews themselves have always been separate from the catalog. But the "preview directory", i.e. the database tables that linked the images with their preview files, has been inside the catalog until LR3.

That created a bit of a trouble for those that had a "copy entire catalog" workflow, the OP was talking about. Namely, even if you had all previews built on both machines, copying a catalog from machine A, invalidated the preview cache on machine B, since the "preview tables" were now pointing to different preview files. And we now that building a new cache takes many hours.

Thankfully, in LR3 those tables had been moved to a separate SQLite database (previews.db file in the root of the preview cache).

RDB_Mac_LR3.5

buy yourself a passport drive, a portable a larger internal harddrive for your lap top. If you value your data, dont mess around with your head in the clouds.

the mind boggles, that is flying faster than time?

Hi,

For instructions you might look at http://www.lightroomqueen.com/downloads/bookexcerpts/lr3excerpts/lr3sa mple-13-movingcomputers.pdf.

Put simply:

If not already done, take care that your images inside LR have 1 common [great-(grand-)]parent folder, e.g. like the default-windows MyPictures.

Copy that over to your new portable drive, as well as the Lightroom-folder with the catalog and previews.

Open your catalog on the external drive and reconnect the missing [great-(grand-)]parent folder to the one on the same drive.

Continue working from the external drive, plugged in on both computers.

This leaves you the plugins and preferences separately on both macs.

But for those you could actually use Dropbox synch, as Victoria Bampton does. Her description about this dropbox use is not part of the free preview reading material, but then you need to spend 14.99British Pound for instant download of her eBook.

Cornelia