Search Results for: preview cache error

Tutorial: Boosting Lightroom Performance

New: Updated for Lightroom 3

Some regular maintenance and a little TLC from you will go a long way toward improving your Lightroom experience and boosting its performance. Here are five things to get you moving faster right now.

1. Free up space on your startup drive. You want to keep at least 15-20% (or more) of your startup drive free and clear of data at all times. Your operating system and some applications need the elbowroom to operate. Running out of space can seriously impact performance. Simple things like emptying your recycle bin/trash, moving data to another internal or external drive or uninstalling unused applications can recover an amazing amount of disk space. Keep in mind that if you are going to move photos to another drive that you should do it from inside of Lightroom.

2. Run your system’s disk maintenance functions. Windows has two utilities that can help you keep your system running in optimal condition—Error-checking and Defragmentation. Double-click My Computer and then right-click the C drive and choose Properties. Go to the Tools tab to launch these utilities. Run the Error-checking first, reboot and then come back and defrag. These can take some time to complete, so you might consider running them overnight.

On a Mac you have the Disk Utility. Open Finder and go to Applications > Utilities > Disk Utility, select your disk and click the First Aid tab. Click the Repair Disk Permissions button. This is good to do before and after you install any application as a regular part of your workflow.

3. Relaunch and optimize your Lightroom catalog. Lightroom has a built-in catalog maintenance function that you can run any time you feel performance is getting sluggish. You probably won’t notice a significant difference on a small catalog, but there is no harm in running this operation. This just performs some basic housekeeping on your catalog and can result in both a smaller catalog file size and a performance boost.

In Lightroom 2, go to Edit > Catalog Settings (On Mac, go to Lightroom > Catalog Settings) and click the General tab. Click the Relaunch and Optimize button. Lightroom will close and relaunch. During startup you will see the Optimizing Catalog progress window, which lets you know it is working. Click the OK button when the operation is complete and Lightroom will open.


In Lightroom 3 this process works a little differently. The big change in Lightroom 3 is that there is no relaunch and optimize button on the Catalog Settings dialog. Instead, just go to the File menu and choose Optimize Catalog. Click the Optimize button when prompted to complete the process.

4. Increase the size of your Camera Raw Cache. The purpose of this cache is to store recently rendered versions of photos you’ve brought into the Develop module to prevent Lightroom from having to re-render them each time, which can greatly boost performance. Go to Edit > Preferences (On Mac, go to Lightroom > Preferences) and click the File Handling tab. Increase the size of the Camera Raw Cache to 20-40 GB based on the amount of free space you have (see Step 1). If you have another internal drive with more free space you can click the Choose button and relocate it to that disk. Click OK to put the settings into effect.


5. Render 1:1 previews after import. This is one of those times where you can pay up front and enjoy faster performance down the road, meaning you will notice a slight performance drag right after the import is complete, but once all the 1:1 previews are rendered you will enjoy a performance boost while you are working later. On the Import dialog there is a setting at the bottom for Initial Previews. This allows you to tell Lightroom what to do about rendering previews immediately after the import process is finished. If you click the drop-down menu and choose 1:1, you can have Lightroom jump right into the process of rendering 1:1 previews right after the import is finished. You will see the progress meter above the Identity Plate increment as it works. You may notice a bit of sluggishness while that is happening, but once it is complete it should be much smoother sailing from there.

Location of Initial Previews setting in Lightroom 2:


Location of Initial Previews setting in Lightroom 3 (top right corner of expanded Import dialog):


The one downside to this is that 1:1 previews are stored in the preview cache (alongside the catalog file) and can take up a fair bit of space over time. To keep from undoing the work you did in Step 1 you can configure Lightroom to discard those large 1:1 previews after a certain period of time. Go to Edit > Catalog Settings (On Mac, Lightroom > Catalog Settings) and click the File Handling tab and choose the interval that makes sense for your needs. There isn’t any reason to set it to Never as Lightroom will always re-render the 1:1 previews if needed at a later date.

Posted in Before You Start, LR2, LR3, Tips, Tutorials | Tagged , , , , , , , | 4 Comments

Don’t Try This at Home

I’ve seen a couple of folks report this problem lately, so I thought I’d put out a general warning against performing this operation in Lightroom 1+. Here’s the scenario … You imported some JPGs. You brought them into Develop and made some adjustments. So far so good. You then think, “I don’t just want these changes to exist in Lightroom, and I don’t want to create duplicates by exporting copies, so I’ll export these right back to the source folder and overwrite the originals.” This is the bad part. You click the Export button on the export dialog and see this:

Problem Exporting Files

[click to view larger]


So, since you intended to overwrite the originals you are thinking, “Great, just what I wanted”, so you click Overwrite. The next thing you see is a popup that says “An error occurred while exporting”:

 An error occurred while exporting

Uh oh. You weren’t expecting that, so you click Show in Library and Lightroom shows you a special collection of “Error Images” which contains all the photos you just exported and they are all sporting new question mark icons. Now you are really concerned so you open a file browser and check the actual folder and find all the photos are gone.  Yep, gone as in deleted.

If you are used to working in a pixel-editor like Photoshop it is normal to save your edits back to the original file, so on the surface it sounds like it might just work in Lightroom too. But it doesn’t. The difference between Lightroom and Photoshop in this scenario is that your original photo is not actually open in Lightroom. What you see is a preview of your original. When you export copies Lightroom grabs the original, makes a copy and then applies the Develop adjustments you made. This produces a brand new file.

So, in our scenario we are asking Lightroom to replace the original with this new copy, but Lightroom needs that original to make the copy! The end result is that Lightroom removes the original to make room for the new version, but then has no file to use for creating the copy with your adjustments. Ouch!

Thankfully in Lightroom 2 beta the option to overwrite originals is turned off. If you attempt the same operation you will see this instead:

 Problem Exporting Files

[click to view larger]

The text now reads “Do you wish to skip the existing files or rename the exported files to avoid collision? You can not choose to overwrite the existing files since some of them are the source files.” I’d love to see the same functionality added into the next Lightroom 1 dot release.

If you are reading this because you just learned this the hard way let me first express my condolences, then direct you to a third-party application that has the ability to export JPGs from your preview cache:


The quality of the copy you can get from the preview cache will be determined by your File Handling choices on the Catalog Settings dialog, but they quality is sure to be 100% better than nothing.  Here’s hoping you never need it.

Posted in Export, Tips | Tagged , , , , , , , | Leave a comment