There are some issues that cause in photography enthusiasts what in the past I've called "angst." That's just the German word for "fear," and it has different connotations in English than it does in German, as far as I can tell. (Ich spreche nicht Deutsches.) A better word for what I mean would be "fretting." A definition of "fret" in that sense is, "To cause to be uneasy; vexed."
I started representing Camera & Darkroom magazine online (on CompuServe) in 1991 and became chief editor of Darkroom & Creative Camera Techniques, a newsstand magazine and quasi-technical-journal, in 1994. I wrote more than 100 columns that appeared on The Luminous Landscape, Photo.net, and Steve's Digicams, and was a columnist for Black & White Photography magazine in England for a handful of years, and I've been running this site since 2005. Believe me, I've encountered just about every form of photographic fretting there is.
All in our heads
Any field, but especially enthusiast hobbies, have esoteric aspects a) which seem like revelations when you first hear about them, b) which seem really important when you plunge into a spate of intensive research about them, but that c) you will be able to restore to their actual level of relative importance the tenth time you encounter them, and d) you recognize as a consistent pattern the 20th time you come across someone raising the alarums about them. Finally, e) you will get thoroughly sick of talking about them by the 50th time they come up...and, in this hobby at least, f) graybeard veterans* have heard them a hundred times—if not five hundred.
I'm not good at putting together comprehensive lists—how do you know you're not forgetting one?—but let's just say that if a bunch of veteran photo writers got together and started brainstorming, we'd come up with a pretty good list of the things that photographers like to fret about. (I even have my pet peeves among them, for instance, how people are so obsessed with sharpness but seldom pay enough attention to tonality.)
A fair amount of this is psychological. There are some things that people just do or don't like as abstract ideas. A simple example: people just don't like flaws and imperfections in the glass of their lenses. Tiny flakes of blacking resting on an interior element, minute scratches, air bubbles in the glass (in older lenses), areas where the coating has flaked or rubbed off—any of these things will reduce the value of a lens considerably. More to the point, they bother people far out of proportion to their actual effect**.
So anyway, on to the topic at hand. On Wednesday, a reader named William responded to Ctein's column about hoarding film by saying, "I can't get excited about...film preservation as a viable long-term plan. Why? four words: Cosmic rays fog film." He then cited a passage from a Kodak white paper about the effects of background radiation on motion picture stock. Good research, and a perfectly valid topic to bring up under the circumstances.
Ctein then answered this concern, saying, among other things, "I am well aware of this. Kodak standards for this, though, are extremely tight, far tighter than typical photographers need to worry about. [...] Moderate-speed B&W still films do not become unusable, not even after decades."
Asked and answered? Not hardly. Since then I've gotten half a dozen sardonic, scornful comments about how Ctein thinks he's such a know-it-all because he thinks he knows better than Kodak does, etc., etc.
So here, for the edification of those still following along, is the long version. Or the somewhat longer version.
There are some films that are known to be excessively affected by radiation; most notably, Kodak P3200 (which probably would have been as ISO 1000 film if it had ever been certified with an ISO rating, which it never was). Kodak lore at the time was that the only place new stock could be stored prior to shipment was in an abandoned salt mine, although I've never been able to confirm if they literally did that. With moderate-speed (ISO 100–400), conventional-emulsion black-and-white films, the very low doses of radiation emanating from the earth and from space—collectively known as background radiation—will not affect the usefulness of the film. On the other hand, it can have an effect on photographic paper, which doesn't last nearly as well in storage.
Why? Well, all you have to do is think about what's going on. Even fresh, promptly-processed film has some density in the "clear" areas—that is, unexposed areas of developed film. That density is known as "fb+f," which means film base plus fog. Why isn't that density significant? Because the clear areas of the film correspond to the dark areas of the print, and the contrast of the print can be adjusted in the printing process to account for slightly more fb+f density—just like it can be adjusted to account for the fb+f of fresh film. As for the highlights, the highlights in a B&W negative aren't "delicate"—they correspond to the dark areas of the negative, which have received so much exposure to visible-spectrum light that a tiny bit of added density from background radiation probably isn't even detectable—the same constant amount of added density capable of doubling the fb+f only adds a tiny percentage of exposure to the dense highlights.
A few cosmic rays just moves the whole characteristic curve up a tad, is all. It's inconsequential because you can adjust for it when you print the negative. It takes a lot of fogging to ruin a negative, far more than background radiation can provide with normal films—even over decades. And if your film does show excessive fb+f as it ages, just add a little more restrainer to the developer as the years pass, and that will control it. (You would be running new tests on your stockpile of film every five or ten years, of course.)
But now think about what's going on with black-and-white photo paper. What areas does a slight amount of fog affect? That's right—the paper base, a.k.a. "paper white"—the highlights. As soon as fog breaks the exposure threshold (paper needs a certain minimum exposure before it will begin to register as density), additional fog registers as a graying of the whiteness of the paper. As it happens, so-called "chemical fog"—the changes that take place within the paper itself as it ages—are more significant than background radiation fog, but in any event, paper can't accept much fog of any kind before it becomes degraded or even useless, for the simple reason that grayed-out highlights seldom look very pleasing. So paper doesn't store for long periods nearly as well as film does, even frozen. Your assuredly-safe zone is about two years, and your limit is going to be about five to ten years, maybe a little more if you're lucky (or if you don't mind a little tone in your highlights). This will vary depending on specific paper brands and types and with each specific storage situation, but it accords pretty well with actual accounts I've heard of or read about by or about photographers who have stocked up on a favorite paper when it was discontinued.
So now, armed with the above information plus your own Holmsian powers of deduction, you can figure out why Kodak has such high standards for the allowable fb+f of motion picture stock. What's a "print" of a film movie? How is it viewed? Which end of the viewable spectrum of tonality/density does fog affect?
Exactly. Kodak is right, but Ctein is also right—you don't have to worry about background radiation as a cause of degradation of moderate-speed, conventional-emulsion B&W (negative) films intended for pictorial use, even when you stash 30 years' worth in a freezer. The film can easily withstand the slight increase in fb+f caused by cosmic rays without becoming even slightly less useful.
(P.S. You're welcome, 11 people out there who have actually decided to stockpile film!)
*Note that Ctein and I both do have actual gray in our actual beards.
**Now that everybody's shooting digital, it's really easy to do the Don Nelson experiment. With your standard utility lens on your camera—normal zoom, whatever—focus your camera on some reasonably detailed subject that's neither particularly near nor particularly far; take a picture. Now tear a small corner off of the adhesive portion of a Post-It Note—maybe half the size of a pea. Stick in on the end of your lens. Now take the same picture again. Compare the two. Surprised? At least now you have a baseline for guessing how much effect that tiny scratch has—the one you can only see when the angle of the light is just so and that's so small you can barely see it without a loupe (and that caused your buyer on Ebay to return the lens to you when you tried to sell it...and the reason you tried to sell it was because that damned scratch just bugged you so much).
Note: Links in this post may be to our affiliates; sales through affiliate links may benefit this site. More...
Original contents copyright 2011 by Michael C. Johnston and/or the bylined author. All Rights Reserved.
Featured Comment by Geoff Wittig: "Living in the Rochester, N.Y., area for many years and knowing many people who have worked in local undergound salt mines, I can confirm that Kodak P3200 was indeed stored there prior to sale. However, marketing hype surely played a large role. The mines routinely rented played-out areas for industrial storage because they provide an extremely consistent environment, requiring zero energy input to maintain 50°F forever. I suspect, though, that naturally-occuring radioactivity in the surrounding rock formations cancels out the reduction in cosmic ray exposure."
Featured Comment by Rico Ramirez: "I went to San Francisco this April and I used black-and-white film over there. Going back I requested the TSA to hand-inspect my film. My camera bag went through the X-ray conveyor for carry-on items. I thought I emptied all the cameras of film but my Hexar AF had a roll of Ilford Delta 3200 in it that was exposed to the X-ray machine. I developed the roll when I arrived home in San Diego and the film came out fine. It wasn't fogged."
Mike replies: I actually had a section in this post about airport X-rays, but cut it because I'm not competent to compare relative doses. (Well, not without doing more research than I want to do.) Generally speaking, though, airport X-ray inspection devices vary in their intensity by a fairly large factor—something like 30X if memory serves, depending on how modern the equipment is, whether you're traveling internationally, the relative wealth of the country you're in, etc.—and, like most radiation damage, the effects are cumulative. So running your film through once didn't hurt it, but running it through 50 times probably would. Now what we need is someone who can compare the rate of background radiation to the rate of airport X-ray radiation....
Featured Comment by John Camp: "There are many different kinds of people plying the waters (and developers) of photography, but because the Internet is what it is—a medium that appeals especially to technically oriented people—you see a lot of people who are more interested in the processes and mechanics of photography than in the images themselves.