[Leica] B&W, color, and archiving images digitally

[Andrew Morang <morang@magnolia.net>]

Dear LUG readers,

Sorry folks, digital data is definitely NOT archival if you are =
referring to being able to retrieve images or data more than a decade or =
so in the future.  Digital has three fundamental problems of great =
complexity that make retrieving data difficult:

1.  The media has to survive.  Diskettes and tapes deteriorate within a =
few years.  Have you ever noticed how bad a casette sounds only 5 years =
after it was recorded?
2.  The software that originally wrote the signal or a close equivalent =
has to be available to retrieve the data from the media.=20
3.  The hardware that wrote the data (or a very close equivalent) must =
be available in operating condition.  Note that this also requires that =
operating systems and other software must be functioning (or must be =
simulated on a newer machine, an exceedingly complex problem in itself).

It is highly unlikely that most of you will be able to read digital =
media that you record today more than 10 or 15 years or so in the =
future.  How many of you have 8-inch diskette drives?  For that matter, =
how many of you have 5 1/4-inch diskette drives, which were quite common =
as recently as 1992? =20

I know about this problem professionally.  At the Coastal Engineering =
Research Center, where I work, it is often impossible to read =
bathymetric data that was collected via electronic means as recently as =
the 1980's.  Often it was collected on computer systems that have been =
discarded, making the backup tapes useless.  So, we spend a fortune =
digitizing paper charts by hand.  Paper is the our archival media.

The most durable media for storing your images is properly fixed and =
washed black and white film.  Film will last a century, and so will =
silver prints.  Retrieval is simple:  you look at the image.  No machine =
is needed. =20

Sorry, I have rambled.  In summary, if you want photographs to hand down =
to your grandchildren, use traditional photographic film, preferably =
black and white.  Your family should be able to retrieve and interpret =
the data quite successfully.

Andy Morang
Coastal Engineering Research Center
Waterways Experiment station
Vicksburg, Mississippi USA