Adobe Photoshop CS5 for Photographers - Martin Evening [245]
Thumbnail settings
If you go to the thumbnail quality options in the Bridge window you can select a policy for the thumbnail generation (Figure 11.17). ‘Prefer Embedded’ uses whatever previews it finds and makes the browsing of non-cached images faster (you can also click on the button to the left to switch to this mode). The ‘High Quality On Demand’ option aims to rebuild accurate previews, but only when you actually click to select a thumbnail. Lastly, the ‘Always High Quality’ option rebuilds the thumbnails for all files it encounters that are not already stored in the Bridge cache.
Figure 11.17 The Thumbnail quality options.
Limiting preview generation
It can take a long time for Bridge to generate preview images of large image files. If you have the Maximize PSD and PSB File Compatibility preference turned on (see page 105) the layered PSD files will generate a composite image layer when saved. This can certainly reduce the time it takes to build each preview in Bridge. If you limit the file size for rendering previews using ‘Do not process file larger than: x MB’ this can also help speed up the time it takes to build a cache of previews of very large files.
If you go to the Bridge Thumbnails preferences (Figure 11.19) you can limit the thumbnail generation to files that are of a certain size or lower (setting a lower limit can help speed up the thumbnail generation). In the Details section you can have extra lines of metadata appear beneath the thumbnails in the content area (as shown in Figure 11.18). The ‘Show Tooltips’ option is useful if you want to learn about each section of the Bridge interface, and does also allow you to read long file names in the Bridge content area more easily.
Figure 11.18 Up to four additional lines of metadata can be added beneath the thumbnails in Bridge. You can use the keyboard shortcut to toggle hiding and showing the text information that appears below the image thumbnails in the content area.
Figure 11.19 The Bridge Thumbnails preferences
Cache management
From the moment you open an image folder in Bridge, the program sets to work: building the thumbnails and previews, reading in the image file metadata as it does so, taking into account things like Camera Raw edits, image rotation instructions, file ratings and labeling. It speedily generates the low res thumbnails first before running a second pass to build the higher resolution thumbnail previews. This is quite a lot of information that Bridge has to process, and if it is your intention to use Bridge to manage large collections of images (especially large numbers of raw files) you really do need a fast computer, or Bridge will appear frustratingly slow. The information that is built up during this process is stored in the form of ‘cache data’, which has two components: the image metadata and the thumbnail cache. Every time you open a folder, Bridge checks to see if there is an image cache for that folder located in the Username/Library/Caches/Adobe/Bridge CS5/Cache folder (you can change this location via the Cache preferences). If a cache is present, the inspected folder displays the archived thumbnails, previews and metadata almost instantaneously. This works fine so long as the folder is being inspected on the computer that created it and the folder name has not changed since the cache was created. If these two conditions are not met, then Bridge has to start all over again and build a fresh cache for that folder.
XMP and Sidecar files
File-specific information that can generally be read by other programs, such as the custom IPTC metadata and Camera Raw settings (Adobe programs only), is normally stored in the file header XMP space. However, because proprietary raw files are an unknown entity it is only safe to store such data within a separate XMP sidecar file that travels with the raw file when it is moved from one folder