In my last post I explained how to use the Photoshop Elements’ (PSE) Copy/Move to Removable Disk feature to move part of your collection to lower cost disk while still retaining visibility within your catalogue.  To make the best use of this feature there are a few caveats, and workarounds for them, you need to keep in mind:

1. No Photo Review/Compare of Offline Images: Despite allowing you to choose offline proxy file sizes as large as 1280 x 960 pixels, the Photo Compare/Review features will not display offline images unless the media is currently mounted.  While I understand the proxy file’s quality would not compare to that of an online file, why couldn’t they just display the "offline file" icon to explain the lower quality image (like they do in the main browser UI)? 
   Workaround: Photo Review can be emulated in the PSE browser by zooming the offline file to maximum size.  Photo Compare can be emulated in a similar way by adding tags/collections to the images, selecting them, then zooming so only two photos appear in the PSE browser.
2. Directory Structure Flattened During Move: All of my photos are stored in a YYYY-MM-MMM\category\yyyy_mm_dd_desc directory structure on my HDD.  When moving photos offline I’d like to automatically retain this relative directory structure but there is currently no way to do so without manually calling the Move Offline function once per destination directory.
   Workaround: Run Move Offline once per destination directory.  e.g. I move photos offline a month at a time.
3. No Way to Identify if Media Online: The Details Metadata query provides no way to search for media based upon whether they are offline or not.  It also provides no way to search by the volume the file is currently stored upon.  Offline photos aren’t automatically assigned tags or collections so this can’t be used to identify the files either.
   Workaround: Assign a tag to photos as you move them offline, and later use this tag to find or exclude the photos.
4. No Way to Move Images Back Online: Hard drives are becoming larger and cheaper all the time, so over time photos that had to be moved offline for space reasons may be able to be moved back online after hardware upgrades.  PSE provides no obvious way to achieve this.
   Workaround: Select files in the PSE browser and use the File\Move option to move files to an online directory.  Alternately delete files from the catalogue and re-import, but if using this approach you should File\Write Keyword Tags and Properties Info to File to retain captions and tags (collection information will be lost).
5. Cannot Bulk Relocate Images on Removable Media/Network Drives:  PSE does not provide any easy way to move the files once they have been moved offline.  This is particularly problematic when having to relocate images as media fails,  or larger media becomes available. e.g. a USB hard drive is lost or fails, or refresh optical media by moving DVD content to larger Bluray disks.  This issue is exacerbated by PSEs insistence on storing network drives as the underlying UNC paths, and identifying optical media by their serial number rather than drive letter, so you can’t just copy the files manually and map them to the same drive letter.
   Workaround: Use the "Move online" workaround, then move the images offline again.

As long as you adjust your digital photography workflow to take these caveats into account, the Move Offline feature remains an extremely useful way to make use of your precious disk space.

With the current popularity of digital cameras and cameraphones, surely my hard drive can’t be the only one bursting at the seams with the sheer volume of photos we are capturing? A quick scan found 26 Gb of photos on my laptop… no wonder I usually have less than 150 Mb of disk space free!  In this post I’m going to explain how to reclaim your harddrive using Adobe Photoshop Elements (PSE) 6’s removable media feature to move lower value photos offline without losing the ability to work with those photos within PSE.

Photoshop Elements Move to Removable Media Feature

I’ve been using a digital photography workflow based upon Peter Krogh’s work in The DAM Book: Digital Asset Management for Photographers.  As a result I have been rating my photos before processing them, and have a number rated Neutral that are of low value and unlikely to be used, but I’m not quite ready to delete.  These are ideal candidates for moving to cheaper and more flexible offline storage to free up disk space.

Adobe Photoshop Elements 6 has a feature that allows you to move content to removable media while still allowing you to see the files within PSE’s catalog.  If you subsequently attempt to edit one of these files, or perform any other action that would require access to the source file, you will be prompted to reload or remount the media the file was moved to. 

When moving photos offline your original file will be substituted with a proxy file: a low resolution version that will be used when viewing the file in the catalog.  The size of the proxy file can be configured using the Edit\Preferences\Files menu option.

My photos are taken using a Nikon D70S that I usually keep in "Raw + Basic" mode.  This means I have two copies of each photo, one in the ubiquitous JPEG  format and a higher quality RAW file in case I need to edit the photo.  To pick my ideal proxy file size I needed to balance the disk space saving against the usability benefits of a larger proxy file.  My tests with a sample photo generated the following proxy file sizes:

I’ve included the generated files so you can gain an appreciation for the quality and size of the proxy files you will be working with in the browser.

As a result of these tests I’ve chosen to use the 800 x 600 proxy file setting.  This replaces 6 Mb of photos with 270 Kb of proxy files, which in rough figures means I could replace my whole photo collection with about 1 Gb of proxy files if I chose to move them all offline!

Moving photos offline

Preparation

Before moving my photos offline I like to write all of my Photoshop Elements metadata to the files, in case I need to access those files from another program or my catalog becomes damaged in some way.  You can do this by selecting a group of files and using the File\Write Keyword Tags and Properties Info to File menu option.  All tag (but not album) information will be written to the images, where the metadata can be read by any XMP aware program.

Writing the tags to file also helps you to capture some data that will be lost during the move.  The File\Copy/Move to Removable Disk function moves all selected files to a single destination directory, so you will be flattening your directory structure unless you chose to move files offline in many smaller batches.  For low value photos I don’t believe retaining the directory structure is worth the effort, but I do use Phil Harvey’s exiftool program to write directory information to a text file in case I change my mind later.  A command such as this:

exiftool -r -m -p "$XMP-xmp:Rating,$Directory\$FileName,$Keywords" * > Ratings.txt

produces a comma separated value (CSV) file such as the following:

1,2007_08_04_LindaAndBenjamin\MSD_20070804_160136.dng,
0,2007_08_04_LindaAndBenjamin\MSD_20070804_160136.xmp,
,2007_08_04_LindaAndBenjamin\MSD_20070804_160140.JPG,Ben S, Linda, Neutral

which should have sufficient information to allow reconstruction of the directory structure if it ever proves necessary to do so.

Execution

To move your photos offline use the following steps:

1. Open the File\Copy/Move to Removable Disk menu option, select the "Move File" check box, and click Next.
   
2. Select the drive you want to move the files to, enter a volume label, select the directory to write the files to, then click Done.
   You will notice in the screenshot that I use a month based directory naming scheme when moving files offline.  This makes it easier to find the files in other programs without requiring much effort to implement.  If my directory structure had been retained by PSE I wouldn’t have needed to bother with this sub-step.
   Please note: If moving files to a large capacity removable media such as a USB harddrive it is not worth uniquely naming each batch or directory as the data does not get referenced in future dialogs or the Browser’s Folders view.
   
3. If moving files to a partially used disk click Yes when the following warning appears:
   "This disk you have inserted is not empty. Would you like to add to this disk?"
4. When the copy step is complete you will see the following dialog:
   "Disk 1 is done…".  Click OK.
5. If you selected the "Move Files" option in step 1), the following dialog will appear.
   
   Click Yes and the online copies of your files will be deleted, potentially leaving the offline files as your only remaining copies.

Followup

Once the files have been moved offline, the files will still be visible in the catalog but will display an icon whenever the removable media is not currently mounted or loaded.  The files will also be visible in the "Offline Media" section of the folder tree in the "Folder Locations" browser view.

Despite the fact that PSE can detect which files are currently offline, the Adobe developers neglected to provide an easy way to search for offline files in the catalog itself.  To work around this limitation I add an "Offline" tag to all photos that have been moved offline.  I considered recording this information using an album instead, but I’ve yet to find a way to search for all photos not in an album (e.g. only find photos not in the offline photos album) so albums could not support my intended workflow.  

Moving them back

Another strange oversight by Adobe is there is no obvious way to reverse moving files offline.  PSE obviously knows that a file has been moved offline onto removable media, but there is no simple "Move file back online" option provided to reverse the process.

Instead you must use the File\Move menu option to relocate the offline files back to online data storage. 

1. In PSE’s browser select the offline files you wish to move back online
2. Select the File\Move menu option. 
3. Browse for the destination directory to move the files to, then click OK.

While this is easy enough to perform there are some notable limitations:

• Proxy files that are no longer required don’t get removed
• Your old directory structure is not restored
• Your new directory structure is not retained

So moving files offline and back will consume more disk space than if you had just left your files online in the first place, and you will lose implied metadata (your directory structure) in the process.