At 03:23 1/9/02, C.H. Ling wrote:
If my memory serve, a report from Wilhelm, Henry published in Pop
photo some years ago mentioned Velvia was tested to be the (or one of
the) most stable E-6 film.
The Elitechorme 100 you mentioned is it EB II? I found this film has
poor shadow noise (very grainy) although looks fine in other area.
Elitechrome 100 is the same as E100S, except it's not aged as professional
films are, and it's part of the second (third ??) generation of E-6
Ektachrome with tabular grain technology. Kodak's catalog number for it is
EB-100; uncertain what you mean by EB II. Haven't evaluated it with heavy
shadows, so I can't state whether it goes grainy in deep shadow.
Quoted from _The_Permanence_and_Care_of_Color_Photographs_ by Henry Wilhelm:
For a 200ss of the least stable image dye in accelerated dark fading
tests at 144 deg. F and 45% RH (figures are in DAYS):
K25, K64, K200: 580
Ektachrome, all: 225
Fujichrome, not Velvia: 185
Fujichrome Velvia: 135
Agfachrome 1000: 75
ScotchChrome 1000: 45
YMMV depending on exact processing method and storage environment, most
notably whether the environment contains pollutants that can damage
film. Processing methods for E-6 vary depending on the exact chemistry
kit. Some labs in the past skimped on the last step which was a stabilizer
(essentially formaldahyde). Kodak has since eliminated it from their
chemistry, but they also changed some of the intermediate process which
skips a wash before the pre-bleach to compensate for it. Apparently Fuji
has not with its chemistry and still uses a conventional
stabilizer. Bottom line: an E-6 lab has got to know what it's doing with
its processing equipment *and* the chemistry it's using; it *does* affect
image stability!!
Some of the recent anecdotal reports of Velvia showing some slight fading
is very likely confounded with labs not processing E-6 properly with the
equipment and chemistry used. At the low end of the most popular
transparency film, it's not surprising it would start showing problems
related to this first, especially when combined with being a high
saturation film.
Comparison with color negative (assuming correct processing):
a. Velvia is about the same as the good archival color negatives.
b. Fujichrome is about the same as some of the better archival color
negatives.
c. The Ektachromes are about on par with the best archival color negative,
Kodak VPS (no longer made; replaced by Portra). *
d. Nothing else comes close to Kodachrome. **
* The early E-3 and E-4 Ektachromes have poor archival unless they're in a
sealed deep freeze; they compare to the worst color negatives and my dad's
archive has a one or two rolls of E-4 (??, could be E-3) to prove it.
** Yes, Kodachrome won't survive projection as long, but that's measured in
single digit hours for both Kodachrome and all the E-6's. Bottom
line: don't continuously project any transparency! Use dupes for canned
slide shows and for sending images to anyone who might leave it in under
projection or on a light table for hours at a time (because they don't know
any better, or worse yet, don't care about your images).
The *worst* places for film storage are in a very humid basement or garage
(with all the paint thinners, insecticides and pool chemicals), or in an
attic subjected to temperature and humidity extremes. Of course, the
method for accelerated life testing is debatable and there are those who
claim Wilhelm is "out to lunch." However, it makes sense to me with the
known enemies being heat and humidity that accelerated life testing would
"turn the wick up" on them.
-- John
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