I’ve just finished my Introduction to Adobe Lightroom Class. This was the fourth time I have offered the course and I have found two important themes that have been consistent throughout each of the sessions.
The other persistant issue that seems to come out of every class is the confusion over the functions of the Lightroom Catalog. This is so essential for the understanding of how Lightroom works that I spend much of my first two hour class discussing the topic, and yet the misunderstandings always seem to linger. Mostly, it must be my fault, but I think sometimes the students are so excited to get to the “sexy” parts, especially the powerful editing functions, that they blow right past the boring nuts and bolts of how the program actually works. At the end of this last class I asked everyone to suggest topics that could have benefited from greater emphasis and it all seemed to come down to the care and feeding of the Lightroom Catalog. It was only after they had manipulated some images, tried to understand where those changes were to be found, and how to translate them to actual flesh and blood image files, that they appreciated the importance of that obscure catalog.
I’ll try to spend more time on the catalog in my next class, but here is another run at a few questions that might help to clarify what the Lightroom catalog is, and perhaps more importantly, what it is not.
Where do Image Files Go When they are Imported to Lightroom
The Database Advantage
Unlike Adobe Bridge, Lightroom is not a file based management system. Lightroom is a database, that keeps track of information about each image file. For each image, the program registers only four pieces of information:
- A set of previews used to display and manipulate the image
- A list of all the editing that's has been applied from within Lightroom
- The Metadata recorded within the file
- The physical location of the file in the computer
|Contents of Lightroom Catalog Directory|
- Catalog Data: [catalog name].lrcat
- Image Previews: [catalog name] Previews.lrdata
- Smart Previews (Lightroom 5 and later): [catalog name] Smart Previews.lrdata
Because Lightroom is a database, which manipulates relatively short text files, it can perform tasks, such as searching and sorting, much more quickly than file based programs, such as Adobe Bridge. This becomes more important when dealing with a large or scattered library. When my own image library exceeded 400,000 pictures, Bridge became impractically cumbersome, and to take advantage of the efficiency of the database model, I finally made the jump to Lightroom.
I can't resist pointing out that, although Melk Abbey's ancient library contains about 100,000 manuscripts, incunabula (printed works before 1500), and books, my catalog has over 400k files, of course of slightly less antiquity.
Keep it in Lightroom : A Disadvantage
Keep it in Lightroom : A Disadvantage
As an image management program, Lightroom is amazing, but it does have disadvantages. Because Lightroom manipulates information about the images and not the image files themselves, it requires more care with the movement of files. It is important to establish the habit of only moving files from within Lightroom. In one sense, Lightroom doesn’t “know” where an image file is, it only knows where we have told it that it is located. Files that are moved outside of Lightroom will be lost to the program, generating the dreaded "!" flag on the files, and "?" marking their directories. These orphans can be found and re-registered, but, a lot of pain can be avoided by following the “Keep it all in Lightroom” mantra.
|Found It : Catabane Falls, Now gone|
Where is the Lightroom Catalog?
The Lightroom Catalog is stored in a directory that can be located anywhere in the computer, but, by default, is found at:
Windows: \Users\[user name]\Pictures\Lightroom
If it is in a different location, it can be found in the Catalog Settings of the Lightroom Preferences.
You can have as many catalogs as you wish. Some photographers keep separate catalogs for work and personal images, but without a compelling reason to compartmentalize your work, a single catalog may be a simpler option.
What Happens when I Edit Images in Lightroom
|Image Edited in Lightroom|
|Actual image is not altered on the drive while|
Lightroom Adjustments STAY in Lightroom
file leaves Lightroom. Stepping out of Lightroom occurs when editing switches to an external editor, such as Photoshop, or when the image is“Exported” to a physical file format, such as jpg, tif or psd. This also occurs when images are shared such as in books, web pages or on social media.
|Export Dialog, Leaving Lightroom|
The key point is that all the editing changes you make are simply a set of instructions that don’t get applied until the image ventures from the warm safety of Lightroom into the dark, pixel based, world, and even then the original Raw file stays intact. That is why there is no “Save” command in Lightroom.
|Wall's End, Guilford Vermont, |
Final image with Lightroom Adjustments Exported the file
The Nondestructive Life
I hope this discussions has helped clarify some of the confusion about Lightroom Catalogs. The more I try to simplify, the more complex it seems to get. I have not covered many related topics such as how to move, combine, rename, back-up or delete catalogs. This could be a topic for a future blog, but all of these details are clarified in numerous articles on the web.
The essential thing to understand is that Lightroom is a database program used to keep track of images on your computer.
When you edit photos, rate them, add keywords to them, or make other changes, as long as you are in Lightroom, the changes are stored in the catalog, but the photo files themselves are never touched.
Don’t you wish life was like this. Try anything you want, take any risk, make disastrous mistakes, and it is ALL “nondestructive”. When you finally like the results just press “Export”.