[Konvas] Storing exposed film

[Rick Garbutt]

Hi, 

It´s me again with some silly questionŠ

How long is it possible to store exposed films? Or, better: Is it possible
to store exposed film for about two months before having it processed? I
exposed two fresh 35mm short ends with the Konvas 1M (Vision2 50D; Vision3
500T), but I do not have enough money to have it processed right now. I
could have it processed right now and I am going to join the victims of the
economical regression these days, but that´s not my first option. So I
thought about storing it a little while ­about 1,5 or two months. Should I
put it into a fridge or even keep it freezed? Or is there no chance for
escaping the risk of fogging of colour detoriation?

Sorry ­I never tried it, always sent it to the lab at onceŠ

Regards, 

Ole 


First off, it's NOT a "silly" question:  it's a perfectly legitimate one.

And the answer makes even more sense if you consider it from the perspective
of "why do they tell you to process film as soon after exposure as
possible?"

The reason film records an image in the first place is that, when a photon
of light smacks into a silver halide crystal, it disturbs the crystal
lattice ("network," near enough), knocking a bromine atom out of position,
and forming the proverbial "latent image," which becomes visible on
development, and permanent with the stop/fix treatment.  (Let's keep this to
B&W for the moment, as it's simpler.  Color film follows similar rules, but
in a more complicated way.)

Right.  Now, with millions of photons hitting the emulsion, we've
essentially turned loose tiny, tiny microbubbles of bromine gas (Br<sub>2),
which are trapped in the gelatine of the emulsion.  Bromine, being a halide
element*, is pretty reactive stuff, and it doesn't want to sit around idly,
especially now that there's a surplus of silver nuclei to play with.

Now, the gelatine, being a large, tangled mass of protien molecules, kind of
gets in the way of things, sort of like you trying to swim in a vat of
molasses.  But you could swim, somewhat, and the bromine can react, but
slowly.  Reforming silver bromide.

So, in simpleminded theory (which has only a little to do with the real
world) if you left exposed film alone long enough, it would "unexpose"
itself.  This doesn't happen in the macro world, but on a micro level, it
does.  And it happens first in areas of fine detail, where there's lots of
space around the silver nuclei for the bromine to get at them and react.
Meaning that you start losing detail, very particularly in lightly-exposed
areas of the negative, to wit:  the shadows.  And in areas of fine detail,
the process tends to accelerate over time.

Meaning that the contrast goes up, and, dadgummit, the image becomes subtly
less sharp.  As you leave the film unprocessed longer and longer, the
mid-tones will start to get messed up, and bear in mind this effect is NOT
uniform across the frame, again, because the damage starts in areas with
fiddly little details.  So tweaking the gamma in telecine won't cure it very
well, if at all.

That's B&W.  If we consider color to be a sandwich of (in modern emulsions)
of at least six color-sensitive layers, each one will react differently
because of the differences in fine detail in each layer.  Meaning as you
leave color film unprocessed for a long time, in addition to the contrast
nastiness above, you will probably see skewing of the color, again, in such
a sense that it cannot be corrected in telecine.

It's not hopeless.  It's a general rule of chemistry that, if things get
colder, chemical reactions slow down.  So if you do have to let some time
elapse between exposure and processing, my advice (which I'm shamelessly
stealing from Kodak and Fuji) is to freeze the sucker.

This should be considered a temporary  and not long-term measure.  Some
rem-jet film stocks (Internegative 5271 was, I recall, bad for this) do not
take well to long-term freezer storage.  I had some of the '71, and
discovered that, after about 2 frozen years, the rem-jet no longer wanted to
remove completely from the cel, and nasty blobs of it were left all over
*^)#!!  And no, you couldn't rewash and buff those off.  The stock was then
good for one thing:  silver scrap recovery.

Bottom line is that Kodak and Fuji are right:  make every effort to at least
process the negative as soon as possible after exposure.  And if that's
going to be more than a week or so, freezing (with the cans taped airtight
shut - gelatine can suffer freezer burn just as a pork chop can) is a
reasonable line of defense.  After a frozen year, you shouldn't be surprised
to see oddball things rear their nasty heads.

Where is it written the world is somehow "fair"?

I hope this sheds some light (sorry:  I couldn't help myself) on this
question.

Best to all,
Rick Garbutt, soc

* the Halides are the period at the extreme right of the periodic table of
the elements, and the original family consisted of fluorine, chlorine,
bromine, iodine, and astatine.  There are late-coming members, but as
astatine is radioactive and it gets worse from there, we don't need to think
about them in the photographic world.  All haledes are very reactive
substances, with fluorine being the worst.  In elemental form, fluorine
tends to react with ANYthing pretty much one way:  explosively. 
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