Lightroom Classic basics

Where do my photos actually live?

The catalog, your photo files, and where to keep each one.

Toby Gelston · McKay Photography Academy

The big idea

Lightroom Classic uses two separate things

Your computer
Runs the Lightroom Classic app
The cataloga file ending in .lrcat

Lightroom's notebook about your photos.

Your photosFolders of original files

The actual RAW and JPEG files from your camera.

They're stored separately. They don't even have to be on the same drive.

The catalog

What's inside the catalog?

  • LocationWhich drive and folder each photo is in
  • EditsEvery slider you've moved in Develop
  • RatingsStars, flags and color labels
  • KeywordsWords you've tagged to find photos later
  • CollectionsGroups of photos you've put together

Think of a library's card catalog. Each card tells you where a book sits on the shelf. The cards aren't the books.

Remember this one

The catalog does not store your photos.

Lightroom Classic does not store your photos.

Why it matters: if you move or rename a photo folder outside Lightroom, the catalog loses track of it. You'll see a question mark on that folder. Move and rename folders inside Lightroom's Library module instead.

The decision

Where should the catalog and photos go?

There are three common setups. Each one has trade-offs.

1Everything on your computerCatalog and photos on the internal drive
2Everything on an external driveCatalog and photos together on one drive
3Split them upCatalog on the computer, photos on an external SSD

Setup 1 of 3

Everything on your computer

Your computer
Catalog
Photos

Good

  • Fast performance
  • Only one extra drive needed for a backup

Watch out

  • Photos and previews fill up your computer's drive
  • Hard to move to another computer

Setup 2 of 3

Everything on an external drive

Your computer

Just the Lightroom app

Plugged in
External drive
Catalog
Photos

Good

  • Fast performance, if the drive is an SSD
  • Easy to move between computers
  • Plenty of room

Watch out

  • The drive must be plugged in to use Lightroom at all
  • Unplugging it while Lightroom is open can crash Lightroom
  • You need two drives: one to work from, one for a backup

Setup 3 of 3

Catalog on the computer, photos on an SSD

Your computer
Catalog
Smart Previews
Plugged in
External SSD
Photos

Smart Previews are small stand-in copies of your photos. They let you keep editing when the drive isn't plugged in. Your edits apply to the originals the next time you connect.

Good

  • Fast performance, if the drive is an SSD
  • Edit without the drive, using Smart Previews
  • Lightroom won't crash if the drive gets unplugged

Watch out

  • Harder to move between computers
  • Backup takes more than one step
  • A big catalog with lots of previews needs room on your computer

Side by side

Comparing the three setups

 1 · All on computer2 · All on external3 · Split
CatalogComputerExternal driveComputer
PhotosComputerExternal driveExternal SSD
SpeedFastFast with an SSDFast with an SSD
Edit without a drive?YesNoYes, with Smart Previews
Move to a new computerHardEasyComplicated
Room to growLimitedPlentyCatalog needs computer space
BackupOne extra driveSecond driveSeveral steps

A real example

Toby's previous setup

This is Setup 2. Everything lived together on one external drive.

Toby's computer

Just the Lightroom app

Plugged in
External drive
Catalog
Photos

Good

  • Fast performance with an SSD
  • Easy to move between computers
  • Easy to back up or mirror photos and catalog together

Watch out

  • The drive always had to be plugged in
  • Two drives needed for an on-site backup
  • Smart Previews didn't help, since the drive had to be connected anyway

A real example

Toby's current setup

This is Setup 3. It's built for travel, when the full archive can't come along.

Toby's laptop
Lightroom folder
Catalog
Smart Previews2015 to 2026 photos
SSD in a laptop pocket
Almost always connected
Originals2026
Archive drives
Another location, connected now and then
Originals2015 to 2026

Every year since 2015 is editable on the road. Only this year's photos travel as full originals.

A real example

How Toby's backups flow

At home

Laptop and SSD
Catalog
2026
Copied to
Archive drives
Catalog
2015 to 2026
Backed up to
Cloud backup
Catalog
Photos

On the road (an extra backup)

Laptop and SSD
Catalog
New photos
Backed up to
Travel cloud backup
A separate bucket from the archive
Catalog
New photos

At home, the archive backs up to the cloud. On the road, the laptop backs up straight to its own cloud bucket.

Recommended for most people

Keep them together, then make a copy

Your computer

Just the Lightroom app

Plugged in
External drive
The one you work from
Catalog
Photos
Backup
External drive #2
An exact copy
Catalog
Photos

One drive holds everything you need. If it fails, drive #2 has an exact copy.

Recommended for most people

Add a cloud backup for a copy off-site

External drive
Catalog
Photos
Backup
External drive #2
Catalog
Photos
Backup
Cloud backup
Catalog
Photos
3copies of your photos
2of them on separate drives at home
1copy somewhere else, safe from fire or theft

Recap

  1. The catalog is a notebook about your photos. It doesn't hold the photos.
  2. Move and rename folders inside Lightroom, so the catalog keeps track.
  3. Keeping the catalog and photos together on one external drive is the simplest setup.
  4. Back up both, to a second drive and to the cloud.

Backed up photos make for a happy photographer.