Understanding the Lightroom Catalog and File Management System

Understanding the Lightroom Catalog and File Management System

The SLR Lounge Lightroom 4 DVD

This tutorial has been transcribed from the SLR Lounge Lightrom 4 DVD, a 14 hour A – Z video tutorial guide on mastering Lightroom 4 including over 6 hours of developing techniques!


It is absolutely vital that every photographer using Lightroom has a full understanding of the Lightroom catalog system in order to prevent workflow issues. While this article may sound basic, even the most advanced Lightroom users will probably find some golden bits in this article, so don’t skip! In this article, we will be covering several main points which are stated below:

1) Non-Destructive Editing
2) Lightroom Previews
3) Understanding the Catalog System
4) File Management
5) One Catalog or More?
6) Recommended Best Practices

1. Non-Destructive Editing

We commonly hear the term non-destructive editing vs destructive editing. But, let’s take a brief moment just to discuss it to make sure we are all on the same page in regards to what is non-destructive editing. Non-destructive editing simply means that any modifications made to an image are not changing the original image. This would mean that with a non-destructive editor (i.e. Lightroom) you would be able to revert back to the original image at any point in time, regardless of how long or how many changes have been made. Photoshop on the other hand would be an example of a destructive editor since changes that are made to an image are saved directly over the original image, thus destructively editing the original file. For this reason, when we work in Photoshop we always suggest that you are work in PSD files and creating multiple layers to ensure that we preserve each change or step all the way back to the original file. So, if Lightroom isn’t actually modifying images, then what are we seeing when we modify develop settings inside of Lightroom.

2. Lightroom Previews

When we see changes being made inside of Lightroom as we are adjusting Develop settings, what we are seeing is actually just a “preview” of what that image would look like were the settings applied to the image. These settings and changes that we are making, won’t actually be applied to the image until you “Export” the image from Lightroom. When you Export the image, Lightroom will take the original file, process it with the settings that were used on that file, and save it as a separate file based on your Export Settings.

Message shown in Lightroom 4 when previews are being rendered

Ever notice while moving from one image to the next (particularly in the Develop Module) that Lightroom pauses and shows “Loading” as shown above? This is Lightroom preparing the image previews on the fly. To save time, we always recommend that prior to developing your images you “Render 1:1 Previews” for all of your images. You can do this by going into the Library Module, turning off all filters so all images are visible, then selecting the following from the menu:

Library –> Previews –> Render 1:1 Previews

This will save enormous amounts of time during developing since Lightroom will no longer have to pause to render a preview when moving from image to image, or when zooming into an image.

3. Understanding the Catalog System

So, given that Lightroom is a non-destructive editor and what we see inside of Lightroom is simply a preview, then what exactly is being stored inside of the Lightroom Catalog file? The Lightroom Catalog file, or .lrcat file, only contains information. In fact, you can think of the .lrcat file as simply a giant database storing the metadata, attributes, develop settings and any other organizational information related to your images. However, the actual images ARE NOT being stored in the Lightroom Catalog. Lightroom is simply referencing those images at a particular location on your hard drive. Knowing this is important because when Lightroom asks you if you want to “backup your Lightroom Catalog” you know then that you are only backing up the information and not the actual images themselves.

During import, there is an actual option where you can backup the actual images in the catalog, however beyond this feature you will need to make backups of your images on your own. This backup option can be found by going to the Import Dialogue (Ctrl + Shift + I or Cmd + Shift + I for Mac).

Then selecting the “Make Second Copy To” option in the File Handling Panel on the right side of the Import Dialogue.

If you wish to make an entire backup of the images within a catalog along with the catalog file directly from Lightroom, there is one other option available.

From the Library Module, Right Click on the folder containing your images in the Folders Panel in the Left Panel display. Select “Export this Folder as a Catalog” and choose a destination as shown below.

dps-article-slrlounge-1This option will take all of the images within the folder and export them as a completely new catalog with its own .lrcat file. It will also preserve all existing develop settings, metadata, attributes, etc. On a side note, it is also useful for making a selection of images, and breaking of just the selected images as a new catalog.

4. File Management

Since Lightroom only stores the information related to your photos, we know that Lightroom has to be pointing or referring to the images somewhere on your hard drive. If you have ever had the ? appear over an image in Lightroom, or had Lightroom tell you a file is “missing” it is because Lightroom has essentially lost the reference to where those images are located as shown below?


This will happen when you move or rename image locations outside of Lightroom. In this situation, you simply need to tell Lightroom where the images have been moved to. For this reason, we recommend putting the Lightroom catalog and the original images into the exact same folder.

So, for example if we just got back from London and I wanted to import my images into Lightroom. I might create a new folder called:

2012.03.01 – London Family Trip

Inside of that folder I would have catalog and images stored in the following folders


It would look like the following:

Because the images and the catalog file are in the same parent folder, if I need to move my catalog I can take everything at once by simply moving the 2012.03.01 – London Family Trip folder. If I rename the same parent folder to something else, the Lightroom Catalog would still link to the images correctly since they are stored in the 00_Originals folder inside of the parent folder.

However, if I need to change the name of the 00_Originals folder at any point in time, this is a change that you will want to make from Lightroom by Right Clicking on the folder and “Renaming” it. If you make this change from your OS file system, then the image locations will be broken inside of Lightroom, and you must update it manually.

If your images are missing, to update the location simply Right Click again on the Folder and select “Find Missing Folder” selecting the new updated location for your images as shown below.


5. One Catalog or More?

We often are asked whether photographers should have only one Lightroom Catalog for all of their images, or have multiple Lightroom Catalogs for every single shoot. There are most certainly benefits to each, the two primary benefits are discussed below:

Catalog Size – The biggest drawback to having a single catalog file for all your images is the catalog size. Despite what Adobe says, Lightroom catalogs do indeed slow as the catalog sizes increase. Now, this isn’t typically noticeable until you reach around 15,000 + images within a single catalog. However, there is a difference. If you do have large catalog sizes, we would recommend using the File –> Optimize Catalog feature from time to time to optimize the catalog efficiency. The other downside to having large catalogs is having large image folders where your images are stored. Transferring or backing up from one drive to another can become extremely cumbersome.

Usability – The biggest benefit to having a single catalog file for all your images is the fact that all your images can be searched, found and edited within a single Lightroom catalog. Since Lightroom catalogs are independent of each other, images within other catalogs cannot be searched and found from Lightroom, unless that specific catalog is open.

6. Recommended Best Practices

So, in regards to the question above, here is what we would recommend, though each one of you will need to make the final decision on your own depending on your workflow and preferences:

The Casual Shooter – For the casual shooter that shoots maybe 10 – 25 pictures a week, we would recommend that you put all of your images into a single Lightroom catalog as you will benefit most from having all of your images stored in one single location. Perhaps every 10 years or so, when your catalog exceeds 15,000 – 20,000 images, then you might want to archive your existing Lightroom catalog and create a new one.

The Frequent Shooter – For the frequent shooter who captures around 50 – 250 images a week, I would recommend that you create a yearly Lightroom catalog file. This will make sure your Lightroom catalogs still remain efficient in terms of speed, while still having decent usability given that to find a particular image, you just need to know the year it was shot.

The Event Shooter – For the event shooter who frequently captures around 1000+ images per event/shoot, I would recommend that you create a Lightroom catalog for each client/event. For the event shooter, efficiency is the primary priority since you need to be able to move through catalogs, edit, transfer and archive at a good speed. The downside here is to find images for say a portfolio, you will need to pull up each client’s catalog.

7. The Lightroom 4 DVD

We hope you enjoyed this tutorial! For those of you that truly want to master every facet of Lightroom 4, be sure to check out the SLR Lounge Lightroom 4 DVD . Quoted as the best and most comprehensive video tutorial guide with nearly 14 hours of education covering every LR4 topic from A – Z including over 6 hours of basic and advanced developing techniques specifically for Lightroom 4.

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Post Production Pye I hate speaking of myself in the third person, haha. I am a Partner and professional photographer with Lin and Jirsa Los Angeles Wedding Photography, and the Senior Editor for SLR Lounge Photography Tutorials. I am passionate about photography as an art as well as my part as an educator in the industry. Subscribe to our YouTube Channel and feel free to hit me up with questions anytime on Facebook.

Some Older Comments

  • Lisa August 10, 2013 01:04 am

    So this would not be a great option to use for a graphic designer to house the images as an image management archive program. I see it only saves certain formats and not pdf or eps...which is what we use mostly.

  • Ian June 15, 2013 02:34 am

    Hi, I have a bit of a problem. After reinstalling my system I changed the partitions on the hard drive (I three and only wanted two) to simplify my storage. Of course, this resulted in the dreaded question mark on the foldes within Lr. In the past using 'find missing folder' has worked, but this time it finds the photos but has no memory of all the developing I did on these photos. Can youthink what I might have done wrong? Or how I might fix this situation? Many thanks in advance.
    - amateur photographer

  • Monica June 5, 2013 02:49 pm

    I just started using LR4 and the whole catalog/collections totally confuses me! What is the difference between the two? When is it better to store images in a collection as opposed to the catalog?

    Another question is when I open LR and want to work on images that I've already imported and worked on, do I open them from the catalog or do I use the Import button to re-open them?

    Thanks for the help!

  • David B May 7, 2013 07:02 am

    While non-destructive editing is one of the greatest features of lightroom it is also a great weakness. I always back up my catalog to a separate drive after every editing session. Archiving a backup every now and then is also very wise.

    I don't know if there is a way to recover your editing, but you should probably best ask on the adobe lightroom forum.

  • Courtney C May 4, 2013 02:55 am

    I use Lightroom for most of my photo editing and I love it, however for some reason, it had changed all of my edits when I went back into the same catalogue the next day. All of the crops were different, the develop settings were where they should be but the image looked like the original... It was heartbreaking because I had spent 10 hours straight editing wedding photos and now everything has changed :( Would you or anyone have any idea why this might have happened? It's never happened before so I don't want to spend hours re-doing them if there is a some miraculous solution. I'm crossing my fingers that you or someone else has come across this problem before!! Thank you! - Court.

  • lynn luzzi December 9, 2012 05:41 am

    I would like use my PC desktop for development, but when I'm on the road, I need to do development on my MAC and would like my full catalog with me....so I am thinking about a Buffalo Ministation external HD (1TB) would have to be formatted as either FAT or exFAT...... how BIG can/does the catalog file get????? FAT can only support about 4 GB file size...exFAT is a bit larger limit). Any insights/suggestions would be appreciated.

  • David B December 2, 2012 08:23 pm

    I do some pano stitching that can have very large files, sometime over a gigabytes worth to do a single image. To speed this up I work in temporary folders on an SSD, but when I'm done I usually zip up all the images I want to keep in one zip for the pano along with the finished jpg and tif images. I then copy those back to my regular hard drive.

    I'm still struggling with how I should be doing this with LR catalogs. How can I make this work flow work well?


  • Mei Teng July 24, 2012 10:47 am

    Great post. I have just recently started using Lightroom 3.

    To make a back-up of my RAW files, I just use the backup option which can be found by going to the Import Dialogue (Ctrl + Shift + I)?

  • Matt July 11, 2012 01:16 am

    Rendering 1:1 previews doesn't seem to work. Immediately after rendering, I'll start culling. No Develop changes, nothing. Just X and 1 as I flip through the Loupe. After a few images, Lighroom shows that dreaded "Loading..." again. I stop, select from that point to the end of the collection, and AGAIN render 1:1, and it renders 30 - 50 images. I start culling, after a few see the dreaded "Loading...", render AGAIN, see 40-60 images rendered, repeat. Until I'm done culling. This is EXTREMELY frustrating, and really completely prevents any sense of speed while culling images.

    My Camera Raw cache is 35GB, and I purge it often. The previews (according to Adobe) are, however, stored in the catalog Previews file, which apparently is limitless. I'm running on a Drobo S, via eSATA, all 7200RPM drives, 2.5TB *free space*, 12GB RAM, a nice i7 processor. This is completely ridiculous.

  • Post Production Pye May 19, 2012 06:53 am

    1:1 previews are stored in your Cache folder, not in the preview folder besides the catalog. Setup your camera raw cache folder in your preferences.

  • abhimayu May 18, 2012 08:41 pm

    great article...

    thankx a lot for the information on lightroom catalogs...i just had 1 question....

    the previews that we render are stored in the previews folder with the lightroom catalog..right?...

    so if i render 1:1 previews for all my photos , the size of that folder will drastically inscrease ...???....

  • Mike Myers May 18, 2012 05:17 am

    I've been working like Simon above where I do most of my work in the Library portion of LR. Your statement about spending 99% of the time in the Develop portion is a real eye-opener and a suggestion I plan to use. It sounds like your workflow would be to use the library to cull the group down to the one's you want to process in the Develop panel, switch to the Develop panel and run through your group of picks. Is this about right?

    I've not spent a lot of time in the Develop panel but I'm assuming there's a way to move through your group of picks without having to return to the Library panel?

    Thanks for the great article and suggestions!

  • to-mas Tomas Halasz May 15, 2012 06:44 pm

    Then it makes sense.
    I use XMPs as dont like to depend on catalog of it broke, its easier to exchange editing values with colleague working on another side of the world and also then i dont need to backup catalogs, just files.
    Thanks for explaining.

  • Post Production Pye May 14, 2012 02:07 pm

    Yeah, we have 3 master photographers, 6 associate photographers, and 3 post production staff. So keeping catalogs small for transferring and editing at max speed is a must. If you are on your own, then it is possible to work in one catalog.

    We don't use XMPs since each change/edit requires two "writes" to the drive as it is stored as an XMP as well as in the catalog. Yeah, once again for speed we don't use DNGs either.

  • to-mas Tomas Halasz May 14, 2012 01:46 pm

    Thanks for reply.
    Yes, if you have a studio where you exchange catelog, than it makes sense. I didnt think about this option.
    I was looking on it from singlephotographers perspective.

    Btw, what about XMP for RAW files? Do you use them, or you have your editing stored only in catalog?
    I assume that for speed you dont use DNG.

    Thanks again

  • Vijayan May 12, 2012 11:27 pm

    Very information and very useful to take decisions in post processing. Thank you for posting this article.

  • Helder May 12, 2012 06:35 am

    Great post. It answers some doubts I have and gives some suggestion for improving my workflow. Thanks.

  • Post Production Pye May 12, 2012 04:15 am

    Tomas, if you aren't shooting that many images, once again, it is fine to have one single catalog as there are obvious benefits. Our studio shoots over 300 events per year and over 1 million images go through production workflow yearly.

    Keeping everything in a single catalog would cause several issues. Primarily, speed reductions. We work through around 500 images an hour, and every second spent on an image is hours when you consider working through thousands. In addition, we have 4 production staff that regularly have to transfer catalogs, transferring would be impossibly cumbersome with catalogs that are terabytes in size. Finding large enough hard drives, backing up images, everything would become an impossible task.

    As for "best pictures" each catalog needs to be searched individually with this system. That is the trade off. Which is why we give the recommendations above based on workflow. Hope this makes sense.

  • to-mas Tomas Halasz May 10, 2012 11:56 pm

    To have a catalog for every event would be a time waste.
    How would you do a search for example, when you need best pictures from events (keyword)?

    I have
    1catalogue for files on main disk
    2 catalogs for each year on external drives

  • Post Production Pye May 10, 2012 03:29 am

    Laurent, it is really up to you. If that system works for you, then go for it.

    I would say though if all 4 catalogs have a combined total of less than 5-10k images, you are probably better off keeping them in a single catalog and separating them by keywords, collections or folders. That way it is all visible and searchable from one catalog.

    However, if each of this catalogs are growing quick, I would keep them the way you have them now.

  • Laurent May 10, 2012 02:37 am

    Very interesting and clear article.
    Concerning the question about one or more catalog, I'm a casual shooter (would like to shoot more but can't find time :( ) but I'm using several :
    - one for family photos
    - one for packshots of my wife home made jewelry
    - one for stuff I sometimes sell on leboncoin (sort of French version of crayg's list)
    - one for studio photo and other studies I do in my photoclub context
    It's an organisation I find quite convenient, what is your opinion about that ?

  • Clay Teague May 5, 2012 01:07 am


    I understand, but I make a backup of the original RAW file during import into LR as well.

    If you do rely on the 1:1 previews, don't forget to change LR's default that deletes 1:1 previews every week or you might get caught without that backup.

  • Dave May 4, 2012 05:30 pm

    @ Clay

    I always use 1:1 previews, not just for speed (I use the 1:1 often during editing), but also for an additional backup. Have you ever deleted a RAW file by mistake and not been able to find it again? It has happened to ne once before, and the 1:1 preview was the only image I had, which thankfully was perfectly fine.

    So perhaps a mention of the feature of LR that stores a JPG of the preview as a last ditch backup?

  • Clay Teague May 4, 2012 12:31 am

    I have used LR since version 1 and would never render 1:1 previews of all my photos as suggested.

    The issue was how LR might be slow at times in displaying your photo as you browse through the images and that rendering a 1:1 preview would solve that problem. Not so.

    First, a 1:1 preview is only required when viewing the image at actual size (1:1). You do not see the actual size image until you click on it to zoom to 1:1 (or whatever your zoom is set to.) As stated, after rendering the 1:1 preview, it will save time when zooming in.

    Also 1:1 previews take a lot of disk space and by default, LR discards 1:1 previews after only 1 week.

    I recommend rendering standard previews during import and let LR create 1:1 previews on the fly when necessary for only those images I need to see as 1:1.

  • Post Production Pye May 3, 2012 05:08 pm

    Simon, the Library Module is actually designed for organization and culling (sorting/rating) your images, not for developing. The quick develop tools in the Library Module are very simple and rudimentary as they are meant just to allow you to get a quick idea of how an image can be produced. Once you have culled your images, then you should switch into the Develop Module to actually develop your images. You should be doing 99% if not all of your editing/developing within the Develop Module. This includes cropping, adjusting exposure, color, contrast, etc.

  • Erik Richard Unger May 3, 2012 04:48 am

    @ Simon

    It can be tough having to press the d key to go to develop and the r to crop and then when you are done pressing enter or return twice to exit the crop tool...

    Not sure how long you have been using LR, but I find it pretty easy and quick to make my way around LR.

  • Simon May 1, 2012 01:13 pm

    Interesting, thanks - however the bit I really don't get about LR is the whole work flow as I find I need to keep switching between library & develop & crop, etc - which all take time to load & multiple key presses. For instance in library, there are the simpler image adjustment settings, but then to make a crop adjustment - one has to first go into develop & then activate crop. Then to go back to the simple image adjustment sliders, one has to go into library again..!

    Is there a way to make this kind of workflow simpler?

  • Gustavo J. Mata May 1, 2012 08:55 am

    Very clear and concise!


    Gustavo J. Mata

  • Alexx May 1, 2012 04:03 am

    Cool post. I hate using destructive editing and if I ever have to, use it I'll make a copy of the original first.