If you've set up your folders systematically, it's not hard to locate images taken on a certain date or during a certain period. However, you need to see the actual images to choose the specific ones that interest you. You can do so with any program that displays your images as small thumbnails. Viewing thumbnails is so important this feature has been integrated into operating
systems and almost every digital camera and photography program. However, thumbnails are only one resource offered by programs designed specifically to manage large collections of images. These image management programs not only let you view thumbnail images and information about the images, they permanently store this information in a database, often called a library. What is a database? In one respect it's just a collection of facts. You interact with databases every day without even knowing it. For example, when you use Google to search for the phrase "digital cameras", you are searching Google's database for Web pages in which that phrase appears. Another familiar database is iTunes' Library where music and information about it are stored. In a database, data (facts) are stored in a very structured way using tables with rows and columns much like a spreadsheet.
A thumbnail image is actually created at the time you take a picture. In a JPEG image it is stored in the image file as metadata and goes anywhere it goes.
Although you never see that actual database, it has one row or record for each image in the library. Each record contains a number of columns or fields that contain specific facts about the image. Typical fields might be the date the picture was taken, the camera used to take it, the size of the image in pixels, and the name of the file. The record for each image has the same fields, and this is what makes the database so powerful. You can sort the table based on the contents of any field. For example, you can sort it by the date pictures were taken, by their size, or format. You can also search the database by specifying what field to search in and what fact to find. For example you
can search the date fields for pictures taken or modified on a certain date. Any images that contain the specified facts in the specified fields are listed. Databases also let you view the information in different ways. You can have it display just thumbnails; or thumbnails, filenames, and image sizes. Another view might include the Exif information so you can see what shutter speeds or lens focal lengths were used for each image.
Lightroom creates a record for each of the images in its database called the Library. You then use Lightroom to view this data, including thumbnails and Exif information, in a variety of ways.
In an image database there is a record (red row) for each image and a number of fields (blue column).
Many image management applications also index and catalog other kinds of files such as movies, sounds, and the like. For this reason, these programs are called by the more inclusive name asset managers—each file on your system from a Quark document to a digital image being an asset.
Database-backed image managers are used to manage small and large collections of images. Their features only grow in importance as the number of photos on your system increases. Here are some of the most important features.
The database in which image information is stored is called a library or catalog. Once a photo has been added to the library, all of the image management and editing tools can be used on it. Some early applications forced you to copy the original image files into the Library so the Library could never be larger than the drive it was stored on, and as the library got larger it got slower. Newer applications let you copy or move photos into their libraries if you want, but also let you reference photos anywhere on your system and even those stored off-line. For example, you can take a CD/DVD or external hard drive out of a drawer, add its contents to your library, and return it to the drawer. You can then view thumbnails and even larger previews of the images even though they are no longer on the system—called off-line. This is because you are actually viewing thumbnails and previews stored in the database when the images were added to the library. Each thumbnail or preview in the library is linked to its full-size image or points to it. If you double-click a thumbnail or preview of an image that's still on the system, the image opens full-size. If you double-click a thumbnail or preview of an image that is on a CD/DVD or hard disk drive in a drawer, the program gives you the name of the disc on which it's stored and prompts you to insert the disc or connect the drive.
If your library ever does get too large or too slow you can create more than one library—perhaps one for professional work and another for personal. However, you can't work on both libraries at the same time so this approach has limits.
Photographers often like to move photos around, rename them, and delete them. If you do this from within the image manager the program keeps track of and accurately reflects the changes.
You can specify that certain folders be watched so when you copy or move files into these folders without using the image manager to do so, they are automatically added to the library. The contents of the folder and the library are synchronized.
You can sort your images in a number of ways including by the date they were taken, their filenames or extensions, and the date they were imported into the database. Sorts can be in ascending or descending order.
Most of the photos we take turn out to be disappointing so we usually focus on just a few photos. For this reason programs let you assign a ranking to images. The best might get a 5-star ranking while the next best 4-stars and so on. Variations of this are to mark them with pick or reject flags or with color labels to which you can attach meanings. Once ranked in one of these ways, you can display, sort, or search using one or more of these criteria.
You can assign keywords to images or groups of images to make it easier to find them later. Keywords can refer to such things as the location, subject, people, and so on. If you are consistent with keywording, you will be able to easily find all of the photos of "Emily" that you took in "Santa Barbara" over the years.
When you have a large number of photos in your library, you may only want to work with a small subset. To determine which images are displayed, you can use filters. For example, you can tell the program to only display pictures taken this week, this month, or on any given day. You can also display just those that have a five star rank or all photos that have been assigned any rank up to a certain level. Filters vary from program to program but all serve the same function—filtering out photos that don't interest you so you can zero in on the ones that do.
When you take a picture, the camera stores information about it along with the image data. You can also add additional information using some cameras and photo-editing or image management applications. The more information you have to work with, the easier it will be to find an image later.
- Exif (Exchangeable Image File Format) is a specification that spells out
how information about a JPEG image is stored in the same file as the image. This information, including a thumbnail image, describes the camera settings at the time the picture was taken, and even the image's location if the camera supports GPS (Global Positioning System). Digital cameras record this information as metadata in an area of the image file called the header. This information isn't just for managing images, it can also be used by some printers to give you better results. Basically, any camera control set to auto at the time the image was taken can be manipulated by the printer or other device to improve results. Those set to one of the camera's manual choices is considered to be a deliberate choice and is not manipulated.
Metadata can sometimes be lost if the file is opened and then saved in another file format. (Or even lost when using the camera's own rotate, crop, or other commands that write to the disk). However, most applications now preserve this information, although camera companies sometimes store secret
metadata that can be lost.
- IPTC. Using an image management application, you can add information to an image such as keywords, a copyright notice, or a caption. The problem is that when you send the image to someone else, that information is usually not sent along because it's stored on your computer in the database and is not part of the image file as Exif information is. (As you will see shortly, one solution to this problem is the xmp file). To solve this problem, the International
Press Telecommunications Council (IPTC) defines a format for exchanging such information. Programs that support this standard let you add, edit, and view this information that's embedded in a file just as Exif information is.
Metadata is data about data. In digital photography it's information inserted into the header of an image file that describes what the contents of the file are, where it came from, and what to do with it. You are already familiar with two examples, an image file's name and the date it was created. Other metadata includes the Exif data created by most digital cameras that tells what camera was used, what the exposure was, and whether a flash was used.
When reviewing your images in detail, you'll generally find thumbnail images too small and full-sized images too slow to open. For this reason image management programs will normally generate full-screen preview images that are then stored in the database. These need only be as large as the screen to be useful. In fact, on some applications you are normally viewing and editing a preview image. You only see the original image when you enlarge the preview past the size where it fills the screen. Since the preview is so much smaller than the original image this increases the application's response time.
One rule of all databases is that an image should only be stored once. When you need the same image to appear in a number of projects, you don't create duplicates. Instead, you create collections, sometimes called albums or projects, of related images. The same image can appear in any number of such collections even though there is only one copy of the image on the system. (If you are familiar with the iPod, this is exactly how playlists work). When you assign an image to a collection, the program just copies its thumbnail and information about it and adds a link to the full-size image. For example, if you have an image that you want to use in both a book and a calendar, you would create collections for each of these projects and add the image to both.
Stacks are sets of related photos such as a series shot in continuous mode or using autoexposure bracketing. By grouping images in stacks you can collapse a stack so only the image you specify as representative of the stack is displayed, or expand the stack when you want to view and compare all of the images it contains. If nothing else, stacks reduce the clutter on your screen because you don't have to scroll through all of the stacked images unless you choose to. Ideally, the application will use metadata, such as how close together photos were taken, to automatically combine some images into stacks.
When working on a project such as a slide show, Web site, or publication, there comes a point when you'd like to see the photos you've taken arranged more like they will appear in the finished work. Film photographers did this by arranging slides on a light table so they could experiment with combinations that would create a particular visual effect. In an image management program an area of the screen provides the digital equivalent; a freeform canvas on which you can place, align, resize and group images in an unconstrained way.
editing means that at any point you can undo any changes you have made to an image.
With RAW images or non-destructive editing the original file is never changed. Your edits are applied when you export an image into another format, to a different folder, or to a file with a different filename. When you do so you can also resize the image, attach a color space, specify a file format and amount of compression.
The latest photo applications use what's called non-destructive editing so an original image is never changed. Instead, your edits are stored in the database and reapplied whenever you reopen the file. When you send one of your edited images to someone, or copy/move it to another system, the edits are left behind in the database. If you want to share the edits along with the image, programs such as Aperture and Lightroom use Adobe's Extensible Metadata Platform (XMP) to embed editing metadata into the image file itself or in a separate "sidecar" file with the same filename as the image but the extension xmp. The metadata can include the list of editing changes you have made to the image as well as Exif and IPTC metadata. Other applications that support XMP can access and use the metadata so you can see the editing changes on other systems.
When you are finished with photos but want to save them, you should be able to archive them along with their metadata. Ideally you can easily select the images and burn them to a CD/DVD or copy them to a backup drive or network volume, and they remain listed in the library so you can see their
thumbnails, previews and metadata. If you select an image that's off-line you will be prompted to insert the disc on which it's stored.
If you want offsite backup, so the same accident can't affect your originals and your backups, on-line storage may be the answer. Two sites, Carbonite.com and Mozy.com, will backup some or all of your files. Each service installs a small program on your system. When you change or add files, they are marked for backup and this is then done in the background while you work on other projects. The only problem with this form of backup is that it can be very slow even with a fast Internet connection. However, after the initial backup of all important files, backups of those files that have changed will go much faster.
Using All of the Features—The Workflow
When a photographer returns from a shoot, their goal is to process images as quickly as possible. Here are some of the workflow steps many photographers might follow in a program such as Lightroom.
1. Adds the photos to the library.
2. Selects all of the images and adds a copyright notice to each.
3. Selects all of the images and adds keywords.
4. Scrolls through the images and ranks them using stars, colors, or pick/reject flags.
5. Delete the rejects, then edits images to be used immediately and exports them in the desired format.
6. Shares or publishes the photos.