In the past few years delivering image files has shifted from CD’s to one of three options: DVD’s, External Hard Drives or Internet Transfer. Which of the three is most appropriate depends upon file sizes, overall job size, speed and convenience. External Hard Drives are most appropriate for large jobs as Internet Transfer is when speed is the mitigating factor. In the middle is delivery of the assignment on disc and a confluence of factors has brought DVD delivery to the forefront – DVD drives have become ubiquitous, the price of DVD discs have fallen, camera file sizes have grown bigger and the speed of DVD burning has increased.
DVD vs. CD
This is an easy choice. A CD holds about 680mb and a DVD 4.4gb (both after formatting). So, if you are delivering large or multiple files that exceed 680mb the DVD is a no brainer. Beyond that though things get iffy… Which media is more archival?
What’s surprising is that a CD is more archival and more fragile. It sounds counterintuitive. High quality CD’s stored under good conditions are estimated to last 100 years or more; that’s great and beats DVD estimates by 3x. CD’s, though, have a backing layer (the top of the CD) adjacent to the data layer. So, a scratch or a mar to that backing layer can make the CD unreadable. DVD’s have a layer in between the top and the data layer. So, a scratch or a mar on the top surface is less likely to affect the readability of a DVD. A stored CD is likely to last much longer than a DVD but a DVD is more likely to stand up to repeated handling.
Disc Delivery – Branding or Lack Thereof
In order to insure the least amount of issues when delivering images on disc I do the following:
-I do not use labels. Labels can come off and destroy a CD/DVD drive, labels can come off rendering a CD unreadable.
-I don’t print on my CD’s or DVD’s via a thermal or inkjet printer. It’s still not clear if printing on a disc will affect its longevity but given the time it takes to burn and verify a disc the possibility of messing up a disc by printing on it is just not worth it.
-Every disc is verified to make sure it burned properly. This is a software process that compares the data on the just burned disc to the actual data on your hard drive.
-Every disc is burned to be compatible with Mac and Widows operating systems.
-I only write on the disc on the inner ring where no data is written.
-I use a solvent free pen to write on the disc. While some people say any marker is fine the consensus is that solvent free ink is the most archival way to go.
-I burn a pdf of the disc cover (contains job information and contents) onto the disc. This keeps the information about the disc with the disc even if the disc and its case part company.
Delivering discs with a nice label or printed top would certainly look better but in this case simplicity is best and providing a problem free disc makes the most sense.
What About Blu-Ray
I get asked this a lot but it’s too early to ask the question. It’ll be a number of years before blu-ray is in wide enough use by computer manufacturers, photographers and their clients to make it viable. It also presents its own problems. Blu-ray will take at least twice as long as DVD to burn. I’m sure even longer to verify. It’s already frustrating enough when a DVD doesn’t pass verification and needs to burned again. To have that happen with 25gb blu-ray discs when you are trying to make a FedEx deadline could be problematic. It may be better to stick with DVD’s.
Some Background Information
NIST CD and DVD Care and Handling Guide
CD and DVD Markers (Google product names to find vendors)
Sharpie CD/DVD Permanent Marker
Update 6/14/08
Delkin has announced Archival Gold Blu-Ray BD-R discs. They claim a service life of over 200 years. The discs start at $27 each. This is still more expensive than DVD’s, gold DVD’s are about $3 ea, and six dvd’s are close in capacity to one BD-R. Other factors, as mentioned above, are still to be determined as to whether this will work for client delivery and while it may eventually become a viable backup medium for photographers it’s still a ways off.