What does it mean when an image is offline? How do images become offline?
Since their introduction in Capture One version 7, catalogs have provided a solution to working with large sets of images with a relatively tiny data footprint and centralized file structure. This is done by caching the preview files within the catalog package, minimizing the need for access to the source raw files. When the original source files are not available, the previews are marked at the top with "?Offline" and the thumbnails in the browser pane have a question mark icon.
While offline, you can still make adjustments and organize images as Capture One does not require the raw file for these actions and will use the cached preview file. However, it is not possible to zoom in past the preview size, process/export or create an LCC from an offline file.
There are numerous ways for an image to become offline, however the root of all causes is the fact that the original file's path is inaccessible. Examples of causes include but are not limited to:
- The drive on which the image is stored is not mounted.
- The original file's filename has been changed outside of Capture One (if this is done within the catalog, the database will update and the image will not become offline).
- The original file's filepath has been changed, either a folder in the path has been renamed (again, outside of Capture One) or the file has been moved to another folder.
- The location of the original file is on a server and passing an inconsistent filepath to Capture One.
- The software or hardware driving the RAID storage device is passing on an inconsistent filepath to Capture One.
- The catalog database has been corrupted and the image entry does not properly link to the image.
For these reasons and more it is abundantly clear that when using catalogs it is best to keep the image files at their original location or to move them from within Capture One rather than Finder/Explorer. Any renaming should be done within Capture One as well to avoid filename issues.
It is also worth noting that the term "offline" is not referring in any way to the internet connection of the machine. There is no cloud-based storage intrinsic to Capture One or catalogs.
How can I bring them back online and get back to work?
The first step in getting images back online is determining why they are offline in the first place; have individual files moved? Is the drive connected? Has the folder been renamed?
If only some images are offline
We can deduce that the individual files have issues. Luckily, we can re-connect them via File > Locate...
This will bring up a system browser with which we can point to the original file. Selecting the correct image will bring the file back online.
If a whole folder or series of folders of images are offline
We can deduce that there is an issue with the path to those images.
First, if the images are stored on an external drive, make sure that it is connected, powered on and mounted properly. If the drive is not mounted, there will be a red indicator next to the drive in the Library tool.
If the drive is mounted (or it is an internal drive), then likely the folder path needs updating. This would be indicated by an exclamation mark icon next to the filename.
To resolve this issue, right click on the folder that is showing the error and select Locate...
If many images recurringly become offline without any user input, this could be indicative of a corrupt catalog database. Select File > Verify Catalog or Session... and point to the catalog file. Select Verify and then Repair if given the option. If it is unable to repair the catalog, you may need to restore the database from a backup, as outlined in Knowledge Base article 1002.