Scanning Photos

added these comments in the current discussion du jour ...

> Does the light from scanning a photograph once or twice,
> damage the photograph?
>
Technically, yes. The light of a scanner lamp varies as to
intensity and color temperature but is pretty bright. But, unless
the photos are very old and hence both rare and valuable, I
wouldn't worry much about it. I scanned all of my old family
snapshots, maybe 500, as well as a subset of my father's WWII
Marine B & Ws and I can't say I see any significant fading or other
damage, but then, I'm just using my eye and not a lab measurement.

--
HP, aka Jerry

"Never complain, never explain" - Henry Ford II
 >> Stay informed about: Scanning Photos 

ray added these comments in the current discussion du jour ...

> On Sat, 01 Dec 2007 19:46:20 -0800, goldie955 wrote:
>
>> Does the light from scanning a photograph once or twice,
>> damage the photograph?
>
> No. No more than viewing it a few times.
>
See my coments to the OP. I think that the typical scanner light
bar or other type light emits a much brighter light than does
normal room ambient lighting, but I don't think it is at all
damaging to the photos.


--
HP, aka Jerry

"Never complain, never explain" - Henry Ford II
 >> Stay informed about: Scanning Photos 

"HEMI-Powered" wrote in message

> added these comments in the current discussion du jour ...
>
>> Does the light from scanning a photograph once or twice,
>> damage the photograph?
>>
> Technically, yes. The light of a scanner lamp varies as to
> intensity and color temperature but is pretty bright. But, unless
> the photos are very old and hence both rare and valuable, I
> wouldn't worry much about it. I scanned all of my old family
> snapshots, maybe 500, as well as a subset of my father's WWII
> Marine B & Ws and I can't say I see any significant fading or other
> damage, but then, I'm just using my eye and not a lab measurement.

True. Think of it this way. If you print a photo and place it in a sunny
window, each moment that the sun is falling on the pigments they fade a
little bit. A days worth of sunlight won't make a noticable difference. But
over time and repeted exposure, the pigments will fade to a nearly
transparent level. The same thing can happen with a scanner or any bright
light. A single or even a hundred scans is unlikely to show any noticable
damage. But eventually, with enough repeted exposures the light can cause
damage to a measurable level.

On top of that some papers, pigments, or chemical coatings may be more or
less sensitive. Thus many museums insist on no flash photography of old
paintings, or old documents as the repeted bright light can have a
degenerative effect over the years.

On the other hand, for most photo prints, simply repeted scanning of a print
would tend to require hundreds of thousands of scans to have a noticable
effect on the print.

JMHO

Randy B.
 >> Stay informed about: Scanning Photos 

Randy Berbaum wrote:

> "HEMI-Powered" wrote in message
>
>> added these comments in the current discussion du jour ...
>>
>>> Does the light from scanning a photograph once or twice,
>>> damage the photograph?
>>>
>> Technically, yes. The light of a scanner lamp varies as to
>> intensity and color temperature but is pretty bright. But, unless
>> the photos are very old and hence both rare and valuable, I
>> wouldn't worry much about it. I scanned all of my old family
>> snapshots, maybe 500, as well as a subset of my father's WWII
>> Marine B & Ws and I can't say I see any significant fading or other
>> damage, but then, I'm just using my eye and not a lab measurement.

> True. Think of it this way. If you print a photo and place it in a sunny
> window, each moment that the sun is falling on the pigments they fade a
> little bit. A days worth of sunlight won't make a noticable difference. But
> over time and repeted exposure, the pigments will fade to a nearly
> transparent level. The same thing can happen with a scanner or any bright
> light. A single or even a hundred scans is unlikely to show any noticable
> damage. But eventually, with enough repeted exposures the light can cause
> damage to a measurable level.

> On top of that some papers, pigments, or chemical coatings may be more or
> less sensitive. Thus many museums insist on no flash photography of old
> paintings, or old documents as the repeted bright light can have a
> degenerative effect over the years.

What is often a lot more damaging than light to ancient pigments is
hydrogen sulphide. The largest source of that in museums and galleries
is people farting. The problem is working out a reasonable way of
banning farters.

--
Chris Malcolm cam.RemoveThis@infirmatics.ed.ac.uk DoD #205
IPAB, Informatics, JCMB, King's Buildings, Edinburgh, EH9 3JZ, UK
[http://www.dai.ed.ac.uk/homes/cam/]
 >> Stay informed about: Scanning Photos 

On Dec 2, 3:39 am, "HEMI-Powered" wrote:
> added these comments in the current discussion du jour ...
>
> > Does the light from scanning a photograph once or twice,
> > damage the photograph?
>
> Technically, yes. The light of a scanner lamp varies as to
> intensity and color temperature but is pretty bright. But, unless
> the photos are very old and hence both rare and valuable, I
> wouldn't worry much about it. I scanned all of my old family
> snapshots, maybe 500, as well as a subset of my father's WWII
> Marine B & Ws and I can't say I see any significant fading or other
> damage, but then, I'm just using my eye and not a lab measurement.
>
> --
> HP, aka Jerry
>
> "Never complain, never explain" - Henry Ford II

Isn't the damage wavelength dependent? I thought the primary problem
was with the blue and UV end. Incandescent lamps do not have much
very blue or UV component, flourescent can, but many do not, so it may
depend a lot on the lamp.
 >> Stay informed about: Scanning Photos 

Randy Berbaum added these comments in the current discussion du
jour ...

>>> Does the light from scanning a photograph once or twice,
>>> damage the photograph?
>>>
>> Technically, yes. The light of a scanner lamp varies as to
>> intensity and color temperature but is pretty bright. But,
>> unless the photos are very old and hence both rare and
>> valuable, I wouldn't worry much about it. I scanned all of my
>> old family snapshots, maybe 500, as well as a subset of my
>> father's WWII Marine B & Ws and I can't say I see any
>> significant fading or other damage, but then, I'm just using
>> my eye and not a lab measurement.
>
> True. Think of it this way. If you print a photo and place it
> in a sunny window, each moment that the sun is falling on the
> pigments they fade a little bit. A days worth of sunlight
> won't make a noticable difference. But over time and repeted
> exposure, the pigments will fade to a nearly transparent
> level. The same thing can happen with a scanner or any bright
> light. A single or even a hundred scans is unlikely to show
> any noticable damage. But eventually, with enough repeted
> exposures the light can cause damage to a measurable level.

Photos printed from some sort of PC printer, e.g., an inkjet,
would seem to me to be different than traditional color and B & W
prints made from a chemical process. I would agree that the dyes
in ordinary chemical prints can and do both fade and get color
shifts, sometimes non-linear across the print depending on where
it was stored.

I would also agree that it would likely take many, many scans to
produce visible damage, not just a couple as the OP's question
would seem to indicate.

> On top of that some papers, pigments, or chemical coatings may
> be more or less sensitive. Thus many museums insist on no
> flash photography of old paintings, or old documents as the
> repeted bright light can have a degenerative effect over the
> years.

The same is true for most anything in museums that are subject to
light damage, e.g., our U.S, historic documents. Some museums
even prohibit flash for more mundane objects, including cars, but
that would seem to be overkill to me.

> On the other hand, for most photo prints, simply repeted
> scanning of a print would tend to require hundreds of
> thousands of scans to have a noticable effect on the print.
>
I don't know about hundreds of thousand,Randy, but certainly a
sizable number. And, you've done an excellent job of separating
the various printing processes and their likely affects to even
bright sunlight.

--
HP, aka Jerry

"Never complain, never explain" - Henry Ford II
 >> Stay informed about: Scanning Photos 

A few passes with a scanner should not cause any noticeable fading
effects on either modern inkjet or recent silver halide color prints
or negatives.

However, several of the posts in this thread bring up relevant topics
affecting print lifetime.

1. The kind of light does matter. Probably most important is the
amount of UV or ultraviolet content of the light. UV light is higher
in energy than light in the visible spectrum and is absorbed
deterimentally by most colorants. Incandescent light (from a tungsten
bulb) has very low UV content, fluorescent light (like that used in
most scanners) is higher in UV, and direct sunlight has even more.
Fortunately some of that UV is filtered by the glass plate of the
scanner. A sheet of plastic between the glass and the scanned object
will remove even more. For the kinds of prints mentioned above (as
opposed to an old, historic photo), such precautions are overkill if
all you're going to do is a few scans.

2. The colorants in both silver halide color papers and ink jet prints
are subject to very similar light fade mechanisms. Pigments, used in
some ink jet systems, can be more resistant to light fade than dyes,
but it also depends on the underlying structure of the colorant. Some
ink jet systems apply a UV-filter coat (as is also found in silver
halide products) or you can do it yourself.

3. All color imaging materials are subject to other kinds of fade in
addition to light-induced dye fade. The three other major factors are
heat, humidity, and pollutants. The latter has been especially
problematic for ink jet materials (the dyes in silver halide prints
are more protected by their gelatin matrix and the organic chemical
phase that the dyes are in). Some ink jet materials, for example, show
quite rapid fade in the presence of ozone, which is formed by any
number of made-made and natural processes. Since most prints (over
95%) are kept in the dark, light fade, in a scanner or wherever, may
be the least important factor in print preservation, especially since
home light levels are relatively low and prints can be displayed
behind glass or plastic.

Bottom line: unless you've got a rare original Autochrome print that
you're planning to scan, don't worry about running your prints through
a scanner a few times. But do remember that digital files themselves
are not everlasting; everything from bit drift to media obsolesence
can limit their lifetimes as well.
 >> Stay informed about: Scanning Photos