In this article we review current options for image archiving.


In this article we review current options for image archiving.
How do you store your digital image files? With digital cameras rapidly replacing film cameras, photographers at all levels must have a system for archiving their image files. Keeping just one copy of each shot on your computer is risky – as many photographers have learned to their cost. Hard disk drives may fail, causing all the data on them to be lost. Image files are also easy to delete, from your camera’s memory card or your computer.

The photo industry is actively promoting printing as the ideal way to preserve digital photos. That’s fine for occasional snapshooters – but serious photographers need more options and the ability to handle many more photographs. In this feature we’ll examine the ideal formats for image archiving and look at some of the technologies you can use for preserving your digital photos.

The main risk associated with any archiving system is accidental data loss. This can occur in many different ways, so you need some form of ‘insurance’ against it. At the very least, a secure archive will have two backup copies in separate locations in addition to the accessible copy of the images that resides on the photographer’s computer.

How to Back-up
Backing up image files is easy. You simply copy the files from one location to another. This can involve copying pictures from a memory card to a computer, from a computer to an optical disk, or from a computer or optical disk to an external hard disk drive.

An effective image archive should ensure there are several copies of your images in different locations. You will probably want to keep one copy on your computer so you can access the files easily. Another copy could reside on an external hard drive that can be connected to your computer and easily linked to another computer when you upgrade your system or swap from desktop to laptop.

Additional copies should be burned on gold DVD media. Once the data is stored on the disk, where it cannot be erased or easily damaged, the disk should be labelled with the date and subject/location of the images. Note: Always use special marker pens for labelling optical disks, not regular markers. Chemicals released from normal markers can degrade optical disks.

Photographers with suitably-equipped inkjet printers may prefer to print labels for their archive disks. Specially coated CDs and DVDs are available for only a little more than regular disks. Note: handle all optical disks carefully and avoid touching the recording surfaces as grease and other contaminants are easily transferred from your fingers.

One copy of these files on disk can be kept close at hand in an ‘archive’ folder, while another copy should be stored at a different location (for example, a security box in a bank or an office). Files can also be stored online and many companies offer web hosting services. Details of all these systems can be found below.
Formats for Archiving
If your camera can capture Raw files, the best option is to archive them as they come from the camera. Although Raw files must be processed into another format (typically TIFF or JPEG) before they can be viewed or edited, the advantages of archiving images as Raw files are significant:

1. The original image is retained, allowing you to return to it when you have new software or hardware that can improve the output you obtain from it. No data is lost when Raw files are archived.

2. The original image metadata is retained. This information includes details of camera settings and photographers can add information about the date the photo was shot, the location, the subject and other descriptors. Copyright data can also be inserted in the metadata file.

But suppose the files originated as JPEGs? JPEG uses lossy compression and each time you open and re-save a JPEG image, data is lost. While a first generation JPEG will offer quality comparable to any other final or ready-to-print format, it cannot offer as much latitude for correcting exposure and other shooting issues as a Raw file.

Both JPEG and TIFF files result from image processing, either in the camera itself or when the files are produced. Certain image parameters must be set by this processing to make the files viewable and editable on a wide range of devices. When Raw or JPEG files are saved in TIFF format these adjustments are locked in, limiting opportunities for further adjustments in future editing.

To minimise data loss, archive all images that originated as JPEGs in TIFF format, using lossless (or no) compression. Do this as soon as the images are downloaded to your computer. The resulting files will be large but storage is now much more affordable than it was in the past. (Some affordable storage options are listed below.)

Storage Options
Photographers can choose from three main technologies when setting up an image archive: optical discs, magnetic tape or computer hard drives. CDs and DVDs are cheap, readily available and convenient. Almost all computers come with a compatible read/write drive, putting this option within everyone’s reach. It’s very easy to burn images to a CD or DVD and both formats can provide a high level of stability and convenience.

CDs can hold up to 700MB of image data, while DVD capacities start at 4.7 GB per disk. But even a DVD will be filled quickly when you shoot with a high-resolution digital camera. CDs are best suited to short-term storage of small numbers of files. Their capacity is too small to make them viable as an archiving option. The higher capacities of DVDs make them a better choice for archiving.

Unfortunately, there can be huge disparities in the lifespan of DVD and CD media. The best choice for archiving is gold discs, such as the Archival Gold disks from Delkin, which are rated for more than 100 years and available from (Verbatim also offers a range of Archival Gold DVD-R discs but gives no lifetime ratings for them.)

Higher storage capacities are available in Blu-ray discs, which are becoming available in computer stores, along with Blu-ray drives. Storage capacities of 25GB and 50GB are available and most drives can also read DVDs and CDs.

Prices of Blu-ray drives have fallen lately and it is now possible to purchase a Blu-ray burner (which can also burn DVDs and CDs) for less than $900. Sony Recordable 25GB discs cost approximately $35 while rewriteable discs sell for around $43. Recordable 50 GB discs are priced at around $84. Average costs per gigabyte for the three types of optical disk media are as follows: ‘archival’ quality CDs – $4; DVDs – $1.15; Blu-ray discs – $1.40.

Magnetic tape systems are still available for business back-ups but they’re seldom used these days for image archiving because individual files are slow to access and the tapes themselves become degraded by repeated use. Most photographers prefer hard disk drives (HDDs), which offer capacities from 60GB to two terabytes.

External HDDs are the most cost-effective option for storing large quantities of digital data. Prices have fallen in the past 12 months, particularly for high capacities, with 1TB (1000 GB) HDDs selling for around $500. Most connect to a computer via a Hi-Speed USB 2.0 cable, which offers data transfer rates of up to 480 megabits/second.

Physical dimensions vary, with models designed to sit on desktops and compact, portable models that can be slipped into a notebook computer case. Larger HDDs require separate power supplies, while smaller models draw power via the USB cable. The beauty of HDDs is that they can work with any computer that has a USB port, so you can easily share them between several PCs. This makes them particularly useful for image and multimedia file storage.

File Organisation
You must be able to locate wanted images quickly and easily, so the hallmark of an effective archiving system is image management. Many photographers work with automatic cataloguing software that will create new folders each time images are uploaded to a computer and allow users to tag individual images or groups of files to make them easier to track. Folders created by such systems can also be copied to archives.

When storing your digital photos, bear in mind that a failure in any of the storage devices you use could mean your pictures are irretrievably lost. It is also risky to rely on automated file management systems as some have been known to behave counter-intuitively at times. You should, therefore, develop a systematic ‘workflow’ – in other words, a standard system for taking, copying, editing and storing ALL your digital images that locks in as soon as you upload files to your computer.

A tried-and-proven system is outlined below.

  1. Shoot all images at the highest resolution and quality settings. (If your camera supports Raw file capture, use it.)
  2. Upload the image files to your computer, using the Copy process, which leaves the original image files on the memory card. If you’re using an automatic image downloader, it should store each batch of shots in a separate folder, labelled with the date on which the files were saved. This is a logical way to catalogue pictures and works well as long as you can remember when pictures were taken. If you don’t use automatic cataloguing you need a system that will make individual image files easy to locate and retrieve. Adding keywords, dates or times to the file name can be helpful at this stage.
  3. Examine your files and delete any images that are unwanted duplicates as well as those you know you will never want again (blurred shots, pictures with serious exposure problems, shots with intervening objects that spoil pictorial composition). Some photographers like to set up sub-files of ‘keeper’ shots at this stage to make it easier to track down their best shots.
  4. Make a second copy of all the image files on a CD or DVD or external hard disk drive; somewhere that is not on your computer’s hard drive. Once this has been done, you can erase the files from your memory card, knowing that if a power surge took out your computer’s hard drive, a copy of your original photos would still be available.

These four steps ensure you have at least two copies of all your original shots. The most dangerous point in handling digital files is transferring them from one storage location to another. To avoid problems, NEVER delete files from the source location until you have verified them in the destination. Other ways to avoid problems when transferring image files include:

  • Make sure the device (camera or card reader) has completed writing before attempting to remove the card or storage media.
  • Avoid wet or dusty places when changing memory cards or writing files to optical disks.
  • Keep spare memory cards in protective plastic containers when they are not in use and store them away from heat, electromagnetic radiation, dust and moisture.

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