March 24, 2018

Photo censorship vs. digital photography

On the 20th anniversary of the Tiananmen Square events (protests? uprising? insurrection? massacre?), the New York Times’ Lens Blog put up a great piece about the four different photographers who photographed the iconic “Tank Man”. Inevitably, half of the story concerns the technical details of being in the right place and having the right equipment configuration to capture the image (no small thing in the middle of a civil insurrection). The other half of the story, though, is about how the film got out of the camera and out to us. The story of Tank Man (NYT article, PBS Frontline piece) is quite amazing, by itself, but I want to focus on the photographers.

Tank Man, photo by Jeff Widener / AP

The most widely seen photo, by Jeff Widener, and all the other good coverage of Tank Man was all taken from one particular hotel, and the government security services were well aware of it. Our photographers had to get their images out. But how? Widener had a “long-haired college kid” assistant who smuggled several rolls of film in his underwear. Another photographer, Charlie Cole, wrote this:

After taking the picture of the showdown, I became concerned about the PSB’s surveillance of our activities on the balcony. I was down to three rolls of film, with two cameras. One roll held the tank encounter, while the other had other good pictures of crowd and PLA confrontations and of wounded civilians at a hospital.

I replaced the final unexposed roll into the one of the cameras, replacing the tank roll, and reluctantly left the other roll of the wounded in the other camera. I felt that if the PSB searched the room or caught me, they would look even harder if there was no film in the cameras.

I then placed the tank roll in a plastic film can and wrapped it in a plastic bag and attached it to the flush chain in the tank of the toilet. I hid my cameras as best I could in the room. Within an hour, the PSB forced their way in and started searching the room. After about five minutes, they discovered the cameras and ripped the film out of each, seemingly satisfied that they had neutralized the coverage. They then forced me to sign a confession that I had been photographing during martial law and confiscated my passport.

In both of these cases, the film was ultimately smuggled to the local bureau of the Associated Press who then processed, scanned, and transmitted the images. This leads me to wonder how this sort of thing would play out today, when photographers have digital cameras, where the bits are much easier to copy and transmit.

First, a few numbers. A “raw” image file from a modern Nikon D700 takes about 13MB and that already includes the (lossless) compression. Back in the film days, the biggest 35mm rolls could hold 36 images (maybe 38 if you were willing to push it on the edges), which tended to keep photographers’ desire to press the button in check. Today, when giant memory cards cost virtually nothing, it’s trivial for a photojournalist to generate tens of gigabytes of raw data in a day of work. So… how long does it take to transmit that much data? Let’s say a hotel’s Internet connection gives you a snappy 1.5 megabits of upstream bandwidth. That means it takes about 70 seconds to transmit one raw image.

If you fear the police will knock down your door at any moment, you don’t have time to send everything. That means that you, the photographer, have got to crunch your pictures through your laptop in a big hurry. If you’ve got the fastest cards and card reader, you’ll be able to copy the data to your hard drive at maybe three pictures per second. Got a thousand pictures on that memory card and you’re waiting a nerve-wracking six minutes to complete the copy.

At the point where you’re worried about somebody busting down the door, you’re not in the frame of mind to tweak with your exposure, color balance, and so forth. Pretty much all you’re thinking is “which one is the winner”, so you’re blasting through trying to select your favorites and then try to upload them.

Meanwhile, we need to consider the capabilities of the adversary. The PRC could well have prevented us from seeing Widener and Cole’s photos, simply by locking down the AP’s offices. (Two other photographers smuggled their raw film out of the country for external processing.) In the modern era, in a country like the PRC, they could just as well cut off the Internet altogether. (We already know that the PRC is cranking up the filtering of the Great Firewall to block Flickr, Twitter, and other services around the anniversary of the Tiananmen Square events, so it’s easy to imagine far more draconian policies.) This places our hypothetical digital photographer in much the same problematic space as the film photographers of twenty years ago. Now we need to smuggle the bits out by hand.

Traveling with film is a huge pain. Higher-speed film, and particularly black & white film, is annoyingly sensitive to airport x-ray scanners. It’s similarly sensitive to humidity and temperature. And, most important, you can’t see it or copy it until you process it, which isn’t really an option in a war zone. Instead, you’ve got the one roll with the one photo that you really want to get out. Alfred Hitchcock would call the film a MacGuffin and would spin a glorious tale around it.

Digital changes all that. Now, even if the Internet is down, the ability to copy bits is incredibly helpful to our photographer. An iPod, iPhone, or other such device will commonly have gigabytes of solid state storage within. That’s not enough room for everything, but it’s certainly enough room for the photographer to make copies of all the good stuff. Similarly, with memory cards getting so remarkably small (e.g., a Micro-SD card is 15mm x 11mm x 1mm), it’s easy to imagine smuggling them in a variety of places. Advantage to the photographer? Certainly so, but also very dependent on how much time and preparation was available before the police busted down the door. The CompactFlash cards used by most D-SLRs (43mm x 36mm x 3.3mm) are much harder to hide (e.g., you can’t just shove one into a crack in the floor).

There probably isn’t much point in trying to encrypt or hide the data. If the police are busting down your door, they’ll just take everything they can find and wipe everything before they give it back to you.


  1. Mitch Golden says:

    The best way to hid a digital flash card is to do what the drug smugglers do – swallow it. You’ll get it back when it passes through your digestive tract.

  2. I believe that swallowing the SD card may be an extremely painful experience, looking at the sharp edges of the card compared to the lubricated condom (or other whatever) filled with drugs. Neither am I sure that the card would survive the journey through the acidic digestion system.

    So Kürth probably has the solution, simply hide the card somewhere inside or on your body and insert another “clean” card in the camera.

  3. dwallach says:

    If the police were smart, they’d be looking not only for your camera and computer, but they’d also survey what adapters you had around. A MicroSD adapter isn’t something you’ll find in many camera bags, which might imply that you specifically had something to hide. At that point, they could well x-ray you to see what’s hiding in your gut (or jail you and wait to see what comes out the other end). Not fun.

    Some cell phones have an internal MicroSD slot and an external USB cable. That’s a nice way to have plausible deniability. Of course, MicroSD-to-USB adapters are pretty small (see, for example the AData adapter that fits into a regular USB connector).

  4. Maybe what we need is a tool that will format a FAT filesystem and pack data into the unused blocks.. Yes, you’d lose data if someone wrote to it, but it would pass a cursory check..

  5. “There probably isn’t much point in trying to encrypt or hide the data. If the police are busting down your door, they’ll just take everything they can find and wipe everything before they give it back to you.”

    If the goal of encryption was to keep you from losing your data, that would make sense.

    Encryption is to keep those police from seeing all of the photos you’ve taken. If you’ve been taking pictures while entrenched with the other side, or getting video interviews with the censored those police can do much worse things than delete your photos. Journalist have a right and a responsibility to protect their sources.

    • dwallach says:

      Okay, I guess the point is that encryption or steganography or whatnot will not help you get the data out. It certainly can protect confidential sources and solve lots of other problems beyond the scope of this particular example. With the Tank Man photographs, however, there’s really no secret that you, the photographer, were in room X and shooting the event as it happened. The police could see you on your balcony with your big telephoto lens.

  6. I R A Darth Aggie says:

    Of course you’ll want spare cards, maybe filled with pictures, possibly encrypted.

    If you’re able to show them what they expect to see, and cooperate in a manner they feel is “full”, and they won’t go digging too deep.

    I wouldn’t expect anything seized to be returned, however.

  7. I’m not a computer geek, so I’m just guessing but I would have thought that it would be a fairly simple technological process to send a low-res copy of the photo whenever you take one.

    Eg. using bluetooth and a PDA/IPhone to have it set up so that every time you take a photo it automatically downloads to the PDA (say, via a USB cable running up your sleeve to), compresses it to a relatively small file, even 500kb, and have your phone send it as an MMS to the home office back in the free world.

    It wouldn’t be any good for proper commercial images, and it wouldn’t be any good for day to day use – but on those times when you’re wandering around taking sensitive photos that you KNOW are going to be prone to local censorship, it would be good to have an instant backup to at least prove that the images existed in the first place.

  8. Courtney says:

    Another thing that’s more problematic with digital as opposed to film in these kinds of situations, is that while the police could expose your unprocessed film, they didn’t know just what (if anything) they were actually destroying, which was exploited in the story in the post. With digital, the police can instantly see what’s on your memory card, and if it’s not what they’re expecting to see (like if you’ve swapped out the card with the pictures on it for a blank one), they can keep looking until they find wherever you hid the pictures.

    With the right equipment, though, you can get around this. One such piece of equipment is the Nikon D3, which has two card slots, and can be configured to write every picture taken to both of the cards. In this kind of situation, you could set up the camera to write every image to both cards, and then remove and hide one of the cards. When the police come looking, they’ll find a card in your camera with the pictures they’re expecting to see. After they delete the pictures from that card (or, if they’re smart, just confiscate the card, since it’s possible to recover the pictures after they’ve been deleted), they’re likely to quit looking, since they’ve found what they’ve came for, and you still have a copy of everything you’ve shot.

    With some more time, it’s possible to do the same thing without any special equipment. You’d copy all of the pictures to a new memory card using your computer, hide the card with the copies, put the original card back in your camera, and delete the temporary copy from your computer. This puts you in the same situation as above.

    • gnaddrig says:

      Having the camera write everything on two cards simultaneously sounds like a good idea. But how long will it take the secret services and police forces of interested totalitarian regimes to find out about this function of cameras? If they check a camera and find one card with the pictures they expect to find and one empty card, but the camera is configured to write to both cards, they’ll smell a rat and go on looking for the other card. if you are after plausible deniability it might be a good idea to change the configuration of your camera immediately after swapping cards. Or, if you have the time, just copy one of the cards, but I guess very often time is something you don’t have if the police are knocking at your door (if they bother knocking at all, that is).

      The next problem is how to get the card out of the country. Swallowing is not a good idea. So I would look for an inconspicuous hiding place. I would probably not use the card slot of a cell phone because if the police are on to you, they would be likely to confiscate any devices used to hold or transfer data: computers, cell phones, cameras, mp3 players etc. So if you hide your micro SD card in one of these you run a high risk of losing it. So I would use other devices that have electronic parts like electrical razors, electrical tooth brushes, maybe radios. You could take some time before traveling into a totalitarian country to prepare one or two spots in your razor. I guess size is not critical in razors, so it should be easy to find a model with a bit of unused space inside. The idea is to unscrew the back of the razor, click the card into the prepared spot and screw the lid back on. Ideally, only one screw would do (you could keep this in mind when shopping for an electric razor). The police would be unlikely to take your razor or toothbrush apart, and if they do, the card might go unnoticed if it is close to other electronic components. Technically, the card would show up on x-rays, but it would not stand out because it blends in with the other electronic bits there. Of course you must not let the police catch you with the back of the razor open…

  9. Anderer Gregor says:

    If the question is, whether you get any pictures out at all, or not, it might be a good idea to backup/upload/… lossy lower-res jpegs first, and the RAWs later, if you still have them, are still alive, etc. It would surely be better for the news agencies to have high-quality pics, but this way they will at least have some pics.
    I think most SRL will be able to write those both at the same time. By the time the local authorities enter your room, you will then have three cards: the one in your camera (in case the authorities are simple enough), the original one (in case they are not, and check the one in your camera first), and a micro-SD, ipod, handy, whatever with the lossy pictures you will still have if they had confiscated the card with the RAW images.

    • dwallach says:

      I like Courtney’s idea of leveraging the dual card-slot feature of high-end D-SLRs to get some redundancy, right out of the gate. I think you could configure JPEGs to go to one card and RAWs to the other card. By stacking up adapters (CompactFlash -> SD -> MicroSD), you could be writing your backup copy directly to a MicroSD card as you’re shooting.

  10. Anonymous says:

    you know how cell phones have a feature that asks you if you want to add a photo to your online archive every time you take a photo, well AP photographers should cameras now that do that automatically after every frame, creating an online storage so that every image is available to everyone only moments after it is taken.

  11. Pascal Scheffers says:

    Both Canon and Nikon Pro bodies have two memory card slots, and the cameras can be configured to save all images to both cards at the same time. In fact, a lot of photographers who own these cameras do this on a regular basis when they shoot once-in-a-lifetime events.

    The second card in the Canon is an SD card. Those are very easy to hide, especially if you know in advance that you’ll have to hide them. You don’t have to be careful with these cards either.

  12. Anonymous says:

    With regard to “incriminating” card adapters, you can flush the adapters or otherwise eighty-six them, and get new adapters later.

    As for internet uploading, a simple way to bypass the Great Firewall if there is working international phone service could be to dial up a modem back home. Either a dial-up Internet account, or a modem at the home office that’s used for exactly this sort of thing (and presumably is firewalled off from the LAN in case someone hits it wardialling; it could be a non-networked box with just the modem, BBS software with files door and ratios disabled, MS-DOS, and little else).

  13. I agree to the ideas and stuff mentioned above, a lot of good ideas. But you ignore one thing:
    The image in the blog article has a size of 72792 Bytes. Yes, that’s 73 Kilobytes. It’s very “small” but still shows the message very well.
    My point here is: If you produce imagery for the press, why do you shoot raw?
    Do you need to capture all the details in the shadows, do you want to postproduce with HDR, do you need to capture the subtle color changes in the camouflage of the tank?
    And – which press photographer has time to do a manual posptprocessing at all?
    Now, if you agree on the fact that a press photographer who is mainly interested in getting an image to his customer quickly can forget RAW as an image format..then things become a bit easier. You basically reduce your “risk” by switching to JPEG. And JPEG is good enough for the press.

    So now you have a small picture which is suddenly transferrable in virtually no time (or, alternatively, you can transfer a lot of pictures).

    This picture must go out (to the agency, to the web) quickly and be replicated asap so that someone who takes your physical media has no hold on your intellectual property. Several comments pointed out “alternative” routes. If you are tech-savy, you can for sure set up such an alternative route, may it be sms, crypted data transfers or whatever, even a classical modem might do the trick (though you better be picky with the number of images then, even at a small size).

    The measures to really stop information leakage, from a dictator’s point of view, have to be extreme to *really* prevent it. Very extreme (eg strip people, x-ray them, put them naked on the flight out of the “combat zone”).

  14. Anonymous says:

    I tend to agree with Dan’s statement about CompactFlash cards that “you can’t just shove one into a crack in the floor”, at least unless you’re extremely dedicated or you’ve had practice doing that. MicroSD cards would make this task much easier and more bearable.

    Still, this has to be the first time I’ve seen that part of human anatomy referred to as a “floor”.

  15. One of the big things that’s changed in the past 20 years is techniques of deep data inspection. Now, if a government wants to keep only certain kinds of files (including encrypted ones) from exiting their borders, they can. Heck, with a little preparation, they could substitute digital photos showing exactly the opposite of what the reporter filmed, right down to matching file size and exif block.

    Back then, blocking the pictures from being transmitted by AP would likely have required blocking AP entirely (even with a working modem or fax tap, the censor would have had to wait until enough of the transmission was complete to be sure of what it was, and then it would be too late). And taking down AP would have been — for much of the western community — as big a deal as the few random protestors and some minor internal-security matter that they were trying to claim for Tiananmen Square.

  16. It doesn’t seem like it would be any more or less difficult to get a compact flash or SD card out than a roll of film. If anything, the card is smaller and more durable than film, so you should have more options. In that situation I wouldn’t even be thinking about trying to upload anything from the scene, but rather how to get the card to a safe location.

  17. Anonymous says:

    Using local point-to-point wireless provides high bandwidth communication to an arbitrary location with maybe a mile radius. This gives the police a very large area to search in order to know where the data is being stored, even if they do know where the picture is taken from.

    Cameras themselves are getting cheaper, smaller and higher resolution. Flash memory storage is down to thumbnail size and thus easy concealable. Then we could go down the track of robot helicopters and small vehicles which are also getting cheaper, more advanced and more widely available.

    In summary, anything that happens in a public place is going to get photographed, and the photos will get distributed.

    Also, in the case of the Tiananmen Square massacre, it has been reported that more than a small number of Party officials were secretly sympathetic to the protesters. They helped with the bigger job of smuggling whole people out of the country after the event.

  18. Anonymous says:

    Reporters in the field going to police states should probably have a way to uplink to a satellite. They can’t easily block that. Just get on a rooftop, push button, little dish tilts to appropriate azimuth and elevation as computed from a GPS unit’s latitude and orientation info, and zzzap!