In this digital age, it is important to know how to preserve your digital photograph collection. The digital image itself is not the only thing that needs preservation. When planning for preservation of digital photographs and images, three major issues need consideration: file format, storage media, and preservation of the original. Discussion on the preservation of original images can be found in part ____. Digital photographs can last many years when stored in the best file format and when properly handled. Other issues involved in the preservation of digital photographs include the quality of storage media and technological changes.
File format is an important consideration to make when planning a preservation project of digital photographs. Although many file extensions are available, only three will be discussed, as they are the most universal. Choosing the right file format for digital photographs is important for two reasons. The first is that the right format can be viewed in a wider range of photograph viewers and editors. The second is that some file formats have a lossy compression while others have a lossless compression.
Just as its name implies, lossy compression loses quality every time an image is viewed, while lossless does not lose image quality. That is not to say that you will see a visible difference in the image from one viewing to the next with lossy compression, but over time, changes will become more evident. If you were to view the lossy compressed file on a daily basis for a year and then compare it to the lossless file, a definite decrease in image quality of the lossy file can be noticed. Basic knowledge of lossy and lossless file compression is needed in order to choose the best file format.
Three common file formats are JPEG, GIF, and TIFF. JPEG is probably the most common file type found on the internet; however, it does not mean that it is the best format in which to store files. Although the files are smaller and more manageable, easier to upload and download, and able to be opened with almost any image viewer, JPEG images are lossy formats. Every time you open a JPEG file, it loses pixels. This includes viewing photographs imbedded into a webpage. GIF file formats are the second most common. Although GIF images are slightly larger, they are comparable to JPEG images in that they are very manageable, easy to upload and download, but not all image viewers can open GIF images. One vast improvement of GIF over JPEG is that GIF images are lossless, meaning that they can be viewed an infinite amount of times and not lose any pixels. TIFF images are probably the most common format for digital photos, but also are probably the least known of the three. Many photo editors use .tif as the default file extension to save images as, yet no one will find many TIFF images online. The reason for that is TIFF images are very large compared to GIF and JPEG images. Although TIFF images are larger than GIF and JPEG, it is highly recommended you save a master copy of the image as TIFF due to their universal nature and lossless compression.
To illustrate the difference in file size between JPEG, GIF, and TIFF, I saved two different images in all three formats. To make sure that the file size remained accurate in all three formats, I made no changes to the actual image, in other words, they were identical in every way other than file extension. The first image is that of Oliver Hackett Wilder taken at the turn of the century in Illinois. The second image was that of the father of William, Mary, and Jemima Coventry, whose given name remains unknown, taken in the mid 1800s in Illinois.
The first image of Oliver Hackett Wilder had a smaller .jpg file size, and subsequently a smaller .gif and .tif size. The file saved as a .jpg totaled a mere 47.2KB, or roughly the size of a long email message. The .gif image totaled 58.7KB, slightly larger. The .tif image totaled 580KB. The Coventry file had a much larger .jpg size. The .jpg image was 578KB, the .gif image was 874KB, but the .tif image was a whopping 5.67MB. Different factors effect file size, including resolution and the size of the image; an 8"x10" digital image will be much larger that a 3"x5".
No matter what the intended use of the digital image is, a master copy should always be saved with the .tif file extension. Although TIFF images take up a lot more disk space, they are the ideal format for master images because they are the most universal image file format. TIFF images can be viewed in any currently existing image viewers, whereas GIF and JPEG images are more limited. Prints of the digital image should come from a file format that is of lossless compression as it will be the most true to life copy. If you save a file as a JPEG and TIFF master, the print should come from the TIFF file. If you save a file as GIF and TIFF master, prints could come from either file.
After creation of a digital file, the file needs to be stored on some type of media. Possible media for genealogists include a computer hard drive, 3.5” disks, USB memory sticks, CDs, and DVDs. Stability of the media, and change in technology are the two biggest considerations to weigh before choosing a type of storage media.
Stability of storage media is an important consideration. Hard drives, 3.5" disks, and USB memory sticks are very unstable, therefore not good choices for long-term storage. CDs and DVDs are relatively stable and therefore constitute better choices in long-term storage. A computer hard drives can crash and usually need replacing within a few years. Due to the nature of the rewritability of 3.5" disks and USB memory sticks, it is possible to lose information by accidentally writing over it or otherwise losing the image. CDs and DVDs are the best types of storage media for long-term storage of digital images; however, the quality of the construction can affect rate of deterioration. There are six types of CDs and DVDs on which you can store images: CD-R, CD-RW, DVD-R, DVD-RW, DVD+R, and DVD+RW. Choosing which to use depends on how much file space you need and how stable the disk is. Rule out CD-RW, DVD-RW, and DVD+RW immediately as their stability is no better than that of a 3.5” disk or USB memory stick due to their rewritable nature.
Through process of elimination, CD-R, DVD-R, and DVD+R are by far the most stable and best media format to store digital images. Being stable, however, does not mean that deterioration will not happen. CD-R, DVD-R, and DVD+R discs experience increased rates of deterioration in five major ways: temperature, humidity and moisture, light, scratches, and a combination of fingerprints, smudges, dirt, and dust. You can break down these five ways into two groups: environmental conditions and improper handling. It is important to note that with poor environmental conditions and improper handling, discs can become unusable in just a matter of days. With proper environmental conditions and handling, they can last for decades.
Although both poor environment and improper handling can be detrimental to the preservation of CDs and DVDs, poor environmental conditions play a bigger role. Although there is a lot of leeway where in the range of temperature and humidity, they can still be detrimental. Ideal temperature can range from 14oF to 122oF so long as change in temperature gradual rather than extreme. Light can be the most devastating environmental condition. We are all aware of how light can be devastating to paper documents (just leave a newspaper in your car’s windshield for a week and see what I mean!), and the same goes for CD's and DVD's. The bottom line is that CD’s and DVD’s, just like paper documents, need to be stored in cool, dry, dark places.
Effects of improper handling, such as fingerprints and light scratches, are very common, and not a major concern. The biggest concerns in regards to improper handling are deeper scratches that make the discs useless and flexing or bending of the discs, which can cause them to break.
Another very relevant consideration, especially in the case of computer hardware and peripherals, is the change in technology. Every few years, new technology comes out, often replacing and leading to the obsolescence of older echnology. You can see this by looking at a timeline of technology. In the 1970s, 8-tracks came out and by the early 1980s were obsolete. The early 1980s brought cassette tapes, and although still available, they are becoming obsolete. 5" floppy drives were the standard in computer peripherals in the late 1980s, they became obsolete by the mid 1990s after the advent of the 3.5” floppy disk. Today, the 3.5" disks are now becoming obsolete with the advent of CDs, and CDs will soon become obsolete with the advent of DVDs. No doubt, eventually DVDs will become obsolete by some new technological advance, which will undoubtedly become obsolete by something else, and the chain continues as long as there are new inventions and new gadgets. So what does this mean for the long-term storage of digital photos on CDs and DVDs? Because of the frequent change in technology, it is necessary to convert files and move them to newer, and often better, media devices in order to ensure their availability to future generations. Despite the storage media chosen, it’s important to remember that with technological changes, images need to be converted to the optimal available media.
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