longevity of processed film

[edgar_njari]

I'm post this in a separate thread after all (mods, you can erase this

post from the "longevity of film" thread, aftet that you can also

erase this part too, thank you

 

the post:

 

1.) How long can I expect a typical modern processed Kodak/Fuji E6

transperency to last before it starts showing color fading, if I DON'T

project it (with ocasional exposure to room lights, lightables, window

light, lamp on a slide viewer etc.) and store it on room temperature?

 

2.) How long would the fading process last before it turns compleatly

magenta or whatever it is supose to turn?

 

3.) How much years would storing in the fridge (about 8 celsious) add

to its longevity?

[larrydressler]

Use Kodachrome.

[randrew1]

It depends on: temperature, humidity, light exposure, environmental pollutants, your definition of acceptability, and which film you choose. There are several definitions of acceptability. Henry Wilhelm has some previously unpublished Kodak data where they estimated the number of years until there was a 10% loss in the least stable dye. Kodak used to publish data where the criteria was a 40% loss. Wilhelm has current comparisons using a 20% loss. If you want to view the original slide, a 10% loss is probably the limit for results one might call excellent. If you are going to scan the slides and correct for contrast loss in individual color records, you can easily accommodate a 40% loss with some tweaking in Photoshop.

 

If you want some numbers, here are Wilhelm's estimates for a 20% loss when the film is kept at 24 C and 40% rh:

 

Kodachrome 185 years

 

newer Ektachrome (introduced since 1988) 220 years

 

older E-6 Ektachrome 105 years

 

E-4 Ektachrome 30 years

 

E-3 Ektachrome 6 years

 

Fujichrome @ 10% rh 150 years

 

Fujichrome @ 70% rh 40 years

 

There is a lot more data where these numbers came from:

 

http://www.wilhelm-research.com/pdf/HW_Book_05_of_20_HiRes_v1a.pdf

 

In the refrigerator, you can multiply these numbers by 2 or 3. In the freezer, you can multiply by 4 or 5.

 

All of these estimates come from Arrhenius tests where film is kept at a series of high temperatures for up to 6 months. The fade rates are fit to an exponential "Arrhenius" equation which is used to extrapolate back to room temperature. It is a very inexact science, but it is the best we've got.

[pics]

Kodachrome has a proven track record of having outstanding archivability. On the other hand Fuji claims 100 year archivability for some of their newer E6 films but I'm not sure if any independent testing has been done and obviously they haven't been around long enough for solid proof. A lot of it has to do with storage conditions such as heat, humidity, as well as indoor and outdoor atmospheric pollutants. Some earlier Ektachrome films stored under less than perfect conditions were known to show significant fading in a matter of a decade or less so it all depends on the variables in the equation. If archivability is of utmost importance shoot Kodachrome (while it lasts) or traditional B+W films.

[r.t. dowling]

<i>obviously they haven't been around long enough for solid proof</i><br><br>

 

The same is true for Kodachrome. Kodachrome, as a general product line, hasn't been around for 100 years... and the current K14 emulsions certainly haven't been around nearly that long.<br><br>Even though Kodachromes from the '60s are generally in better shape today than Ektachromes from the '60s, that doesn't mean that Kodachromes from 2005 will hold up better than Ektachromes and Fujichromes from 2005 20 or 50 or 100 years from now.

[garethspics]

I have noticed some variability with Kodachrome. One film I took in the Himalayas in 1983 has a noticeable magenta hue in the whites, but the next one is much better. They have been stored together. I have a number of films from the 1950's which are perfect. There has been no appreciable fading on any of them.

[helenbach]

Apart from the predicted life of the image, it may be worth considering the stability of the base: acetate base is comparatively less stable than polyester. For example, ISO 18901 (Stability of silver-gelatin B&W film) only permits polyester based film to have the highest classification of LE-500. Acetate based film is restricted to the next classification down: LE-100.

[jtk]

Almost all comments about fading and change are urban legends.

 

I've seen Ektachrome E3 turned magenta after about ten years.

 

The main problem is bad processing.

 

I have a lot of E4 that my lab processed in the Seventies that looks fine today, though some is slightly desaturating..certainly no color shift. I have E6 sheet film from the Eighties that has not visibly changed at all, judging by comparison to their lithographic tear sheets. All of this was stored at room temperature in various film boxes. Even the stuff I carelessly left in Visfile polyethylene pages has stayed color-stable, though some has been etched by degassing.

 

Kodak's Palo Alto lab and Dallas lab, and several professional labs in the United States did a good job with Ektachrome E4. Most professional labs did very bad work with E4, giving it an undeserved reputation for looking greenish.

 

Many labs are doing good work with E6 today, including one in my own city. Some are obviously running dirty chemistry, the result of tolerating cross processing. That doesn't relate to longevity, however. If they're a professional lab, they're running the film in a dip and dunk machine or on reels in nitrogen burst systems. No rotary machines, obviously.

 

Kodachrome can change as rapidly as E6 (or E4), depending on who processed it (was it Kodak in Palo Alto or Dallas, or Pathe in Paris, or was it one of the inferior labs?

 

Now there's only one Kodachrome choice in the US... The look of their film at the time of processing is no clue to longevity, you'll have to look again in twenty years.

[randrew1]

"Almost all comments about fading and change are urban legends."

 

I agree that processing makes a big difference. I have two rolls of Kodachrome that are badly stained because of bad processing. It is a bit of an exageration to say that all comments about fading are urban legends. I can confirm some of Wilhelm's predictions from personal experience.

 

Aside from two rolls that suffered bad processing, all Kodachrome in the family collection back to 1938 show no evidence of fading.

 

All E-3 film shows significant fading. This would make a good challenge to the group. Does anyone have an unfaded E-3 image that was stored at room temperature?

 

The E-4 slides are starting to show some fading.

 

I have yet to see any fading yet in E-6 film.