1 person found this helpful
First of all, create a parent folder for your photos on the new external hard drive. All the photos you take when travelling should go into this folder, or in subfolders.
Then create a new catalog in LR on your laptop, and note its location.
When you get back home, copy the parent photos folder with all its contents to your home external drive.
Also copy the folder containing the Lightroom catalog from the laptop to the desktop.
Now launch Lightroom on the desktop, and go to File > Import from another catalog.
Navigate to the catalog (.lrcat) that you copied from your laptop.
In the dialog that appears, under File handling, choose Add new photos to catalog without moving, then click Import.
Thank you very much for taking the time to answer this. This is exactly the detail that I've been looking for!
I have never done this myself, and having given it some thought, I see one potential problem you might come across.
Let's say that the external drive on your laptop gets drive letter D assigned. Lightroom then expects to find the photos on D.
When you connect this drive to your desktop, it might be assigned another drive letter, for instance G, and Lightroom can't find the photos.
Edit: Your desktop external drive might have a different drive letter, in which case Lightroom can't find the photos.
To prevent this from happening, before you do the import from another catalog, on the desktop, double-click the .lrcat file from the laptop.
This will launch Lightroom with the laptop catalog, and if the drive letter has changed, all the photos will be missing, and all the folders will have question marks on them.
Right click the parent folder, and navigate to the correct location of the folder, and the question marks should go away.
Then open your regular desktop catalog, and do the import from another catalog.
If you have time before you go, you could do a test run of the whole procedure. Good luck!