----- Original Message -----
From: "Randy Little" <randyslittle@xxxxxxxxx>
To: "List for Photo/Imaging Educators - Professionals - Students"
<photoforum@xxxxxxxxxxxxxxxxxx>
Sent: Friday, June 14, 2013 11:01 PM
Subject: Re: Keeping images safe Was: golden age layoffs
I don't KNOW how long they last I just know that un powered they start to
de magnetize some last a long long time some don't. Most do but they
aren't considered archival storage.
http://www.larryjordan.biz/hard-disk-warning/
this is really weird: " Magnetic signals recorded on a hard disk are
designed to be refreshed periodically. If your hard disks stay on, this
happens automatically. However, if you store your projects to a removable
hard drive, then store that hard drive on a shelf, unattached to a computer,
those magnetic signals will fade over time. essentially, evaporating"
there is effectively magnetic iron 'dusted' onto platters, no different from
tapes, (the other white meat) which can be demagnitized with a powerful
enough magnet (like a REALLY dangerous and big NIB magnet, which will
probably snip off a toe and a finger or two as you're manipulating it near a
drive) but hey - physicists still pull polar shift data from old fires
based on the way the magnetic fragments were laid down 10,000 years ago.
"According to what I've been told"
oh dear (searching magnetic fading on gogogle brings up a lot of Larry)
"the life-span of a magnetic signal on a hard disk is between a year and a
year and a half. The issue is complex, as you'll see, but this is a MUCH
shorter shelf-life than I was expecting."
there are enough issues with hard drives without rumours and myths clouding
the issue.
I think all of us have 10 or 15 year old drives we've dusted off and checked
for backups with no problems at all. However, 'electronics' are funny
things, the electronical bits always behave fine, however they are
mechanical too and often if not always it's the mechanical bits that fail.
Drive motors seize, heads freeze, solder becomes brittle and cracks - and
my pet hate (curse consumer advocates) the new lead-free solder grows tin
'whiskers' which short circuit the electronics. ..If you have old drives,
keep them! All our new electronics post-lead will kill themselves sooner
rather than later - that's why digital TVs and the like fail so quickly,
well those and the cheap dodgy electrolytic capacitors that swell up and
vomit acid across your circuit boards.
Tin is weird stuff and a horrible replacement for solder. In time without
lead to amalgamate it, it starts to crystalize, growing strands of tin
outward as well as becoming more brittle- now in clunky old electronics this
was less of an issue, but as the tracks become finer and the voltages and
currents lower and lower, these whiskers will probably make contact in some
undesirable location and that'll be that. short circuits don't blow
themselves when you talk microamps
Another hard drive issue I've encountered recently which disturbs me is
non-standard interfaces: most drives have parallel (IDE or PATA) , SCSI or
serial (SATA) connections on the boards - the green bit attached to the
block of aluminium which holds the platters. Same as you'd find inside your
PC or laptop. If the drives fail, often it is because of a failed drive
controller board - this board can be swapped with an identical board from an
identical drive and usually the data can be recovered with little effort.
these bare drives of whatever flavour can be found inside external drives,
most frequently with a converter board as well, something like IDE to USB or
SATA to USB. occasionally these auxiliary board fail but that's even
easier, you pull the drive and stick it in a USB cradle and away you go.
Its good this way, you have 2 levels of potential failure, but both are
easily circumvented.
Unfortunately the new western digital passport 2.5" drives (and maybe other
brands) controller board is USB only, not IDE or SATA. I had one handed to
me for data recovery and went trying to locate a replacement board but all
the data recovery Co's had snapped them up and were selling older boards for
20-50 times their purchase price (eeek!) Want to pay $3000 just for the
board to recover data from an old 120Gb passport? neither did the owner..
especially when they found out that the board probably wouldn't work - as
frequently these USB boarded drives have their platters mapped to that
individual board ! All fine if your drive was perfect from the factory and
the replacement drive was also perfect - the odds of that though are zip.
so be warned, use those 2.5" drives only to move data, do NOT rely on them
for archiving.
http://en.wikipedia.org/wiki/Media_preservation **
**CDs and DVDs have finite shelf-life due to natural degradation of the dye.
The National Archives and Records Administration lists published life
expectancies to be between 25 to 15 years for CDs and DVDs and conservative
life expectancies to be between 5 and 10 year.
**Magnetic Media also deteriorates naturally with typical shelf-lives
between 10 and 20 years
as an aside, some things I've noticed pertaining to image longevity:
I have photographic colour prints from the 40's which look good as new
(Agfa), and plenty from the 80's which look fantastic. Mind you, those ones
were washed and not stabilized.. stabilizers were formalin based
preservative baths that saved water at the expense of print lengevity. They
woulkd inevitably destroy the dyes in time. I even set some aside from the
printers untouched and some I washed, the washed ones still look fine, the
unwashed ones faded to orange. As far as I know stabilizers still use
formalin, and they're often included in the final bath.
E6 films were often stabilized too, in 'water saving' E6 machines, even dip
and dunk machines used a formalin based stabilizer bath unless the clued-in
tech decided to drop that part of the process.
RC papers got bad press, often because from mistaking POP papers and the
efforts of canny photographers who's proofs went unfixed , for well
processed prints . RC papers will probably outlive most if not all 'fibre'
based papers. They certainly resist insects, fungi and rodens better.
To the best of my knowledge and testing, modern FB papers are NOT linen or
hemp based as they were in much earlier times but are wood pulp or at best
cotton. Both are vastly inferior to FB papers of old. I even tested some
supposedly hemp papers and found them to be a combination of cotton and wood
pulp. Those old papers we admire so much were totally different materials
to today.
Polyester such as Ilfoflex, Ilfochrome and Ilfords inkjet polyester based
'papers' will outlast anything. The colours *may* go in time like any
colouring agent, but the base will remain (and while they remain a picture
they look amazing!)
Print and neg washing is taken too far by many printers. A perfectly washed
print will fade from oxygen attacking the pure silver far quicker than a
poorly washed one in which the thiosulfate breaks down and reacts with the
silver to form silver sulphide - a sepia protective layer. Think about it,
all fix as it becomes overused will precipitate silver metal (albeit silver
coated with sufide) - it does NOT disolve metalic silver, only silver halide
salts just as it was designed to do.. and think back to those old books
where they advocated boiling old fix down to a concentrated form to use as a
poor-mans sepia toner. Those old guys weren't idiots, often they were
amateur chemists. Not suggesting you don't wash prints - just don't go
nuts.
Sepia toning is vastly superior to selenium - the old Kodak selenium formula
used thiourea in it (sepia), the modern one does not. Microfishe testing
showed only the old toner preserved the images with sulfur-free toners being
susceptible to oxygen damage (or redox bleaching as it was termed). Sepia
toners resolved this fault.. ergo, it was never the selenium doing the
protecting. It does though if you bleach the silver back entirely and
redevelop in selenium.. but then you may as well go platinum, paladium or
gold - less toxic.
For my prints to last the ages I will print of RC papers and sepia tone.
k's 2c for the day
