Look at the difference between these films - CT scanner exposure

Can you see the difference in density?

Both are cut from the same 100ft roll of bulk film, and both were developed together in the same tank for six minutes with normal agitation. Can you guess the difference between them?

The top one you either intentionally fogged, or it went through an x-ray scan multiple times...

djdister said:

The top one you either intentionally fogged, or it went through an x-ray scan multiple times...

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Correct! Twice through an airport scanner.

Must have been CT scanner then. Regular X-ray don’t do that in my experience.

Nitroplait said:

Must have been CT scanner then. Regular X-ray don’t do that in my experience.

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… as quickly. Maybe after 20 passes…

Nitroplait said:

Must have been CT scanner then. Regular X-ray don’t do that in my experience.

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Yes, one of the two scanners was a CT scanner.

Thank you for showing this.

That's pretty rough indeed.

This is why I have stopped traveling with film, too complicated, make sure no film in camera, hope that the custom or security person will hand check etc. I will either buy film once I get there, have in developed prior to departure or mail it home and hope the shipping company is not using a CT scanner or just use digital. ,

I tried this as an experiment once (HP5 also) but with a longer strip. Besides the fog level there were also darker patterns, so it would effectively ruin any images rather than just add density.

AZD said:

I tried this as an experiment once (HP5 also) but with a longer strip. Besides the fog level there were also darker patterns, so it would effectively ruin any images rather than just add density.

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Yes, the photos were mostly ruined

cerber0s said:

Yes, one of the two scanners was a CT scanner.

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I have had different experiences with the new CT scanners at airports. In most cases, films are undamaged, but with a bad luck, they can be totally destroyed. One weird experience was having about 10 rolls of film scanned, HP5, FP4. Portra 160. amd Portra 400. All the other films were visually fine, except for one roll of Portra 160, which had uneven fog marks in almost every frame. I have to use airports where requests for hand check are almost always denied.

Thanks for doing this experiment for us. It demonstrates that CT scanners can do real damage, though I am equally sure people sometimes get lucky.

Thankfully we're now getting a lot of data from real life situations where people are able to get film hand inspected at airports around the world. This certainly won't stop me travelling with film.

Agulliver said:

Thanks for doing this experiment for us. It demonstrates that CT scanners can do real damage, though I am equally sure people sometimes get lucky.

Thankfully we're now getting a lot of data from real life situations where people are able to get film hand inspected at airports around the world. This certainly won't stop me travelling with film.

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It kind of depends what you mean by salvageable. You could make out what they were. A few that had an abundance of light came out OK. I've scanned them, but they were bad enough that I just dumped the negatives in the trash.

I also shot a few rolls of Adox CMS 20, those came out just fine.

Please explain what a CT scanner is?

Loren Sattler said:

Please explain what a CT scanner is?

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From a Google search:
and as applied at airports:

@cerber0s ,
For purposes of helping people find this thread if they are researching the subject of CT scanner effect on film, we would like to add a reference to CT scanner exposure to the thread title.
Your thoughts?

MattKing said:

@cerber0s ,
For purposes of helping people find this thread if they are researching the subject of CT scanner effect on film, we would like to add a reference to CT scanner exposure to the thread title.
Your thoughts?

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Absolutely!

cerber0s said:

Absolutely!

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Done!

Paul Howell said:

This is why I have stopped traveling with film, too complicated, make sure no film in camera, hope that the custom or security person will hand check etc. I will either buy film once I get there, have in developed prior to departure or mail it home and hope the shipping company is not using a CT scanner or just use digital. ,

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For sure the best solution.

Agulliver said:

Thanks for doing this experiment for us. It demonstrates that CT scanners can do real damage, though I am equally sure people sometimes get lucky.

Thankfully we're now getting a lot of data from real life situations where people are able to get film hand inspected at airports around the world. This certainly won't stop me travelling with film.

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I fly a lot for work (including outside the U.S.) and almost always carry a film camera with me. I can offer a few tips based on my experiences, especially ones I've had over the last 3-4 years since CT scanners started becoming more common at airports:

1) (Most people probably already know this one, but...) Don't put film in your checked baggage. Checked baggage screening typically utilizes either higher-intensity X-ray machines (compared to the X-ray machines used for carryon-on screening) or CT scanners, both of which can do observable damage to film.

2) (Most people probably already know this too, but...) Remove any film from your camera before going through passenger screening at the airport (i.e., where they check you and your carryon items). Security personnel, in most cases, will not be willing to do a hand-inspection of a camera, especially an electronic one, which means that any film still loaded in it will have to go through the scanner along with the camera. That's usually not a big deal if it's an X-ray machine but can be a problem if it's a CT scanner.

3) Put your carryon film in a clear, Ziplock-style bag (as opposed to something like a lead-lined Domke film bag). If the security worker you ask for a hand-check from can immediately see what's in the bag, they'll be much more willing to agree to the request. Those lead-lined Domke film bags are nice for storing film (i.e., they're dark inside and have a Velcro enclosure) but they're basically useless now for air travel purposes. They offer minimal protection against CT scans and aren't needed in most cases for X-ray machines, as most people aren't using film that's higher than ISO 800.

4) Regarding Domke bags specifically: If you do choose to use one for transporting film through the airport, don't send it through a CT scanner; ask for a hand check instead. It won't offer much (if any) protection against CT scanning and it'll almost always trigger a secondary screening request by the scanner operator, which means the film will get pulled out and hand-inspected anyway. With an X-ray machine, you can safely send a Domke bag through it (that's what these bags were made for), but be aware that doing so will similarly trigger a secondary screening request due to its opacity to X-rays. Domke bags are nice for film storage when you get to where you're going, so I'd suggest packing it (empty) in your checked luggage and packing your film in a Ziplock bag while moving through airports.

5) Learn to recognize the difference between an X-ray machine and a CT scanner. An X-ray machine generally has a square or rectangular profile and will look older (often with an aluminum or stainless steel exterior), while a CT scanner generally has a round or oval profile (though, I have seen rectangular ones) and will look new (they often have a white or beige-colored plastic exterior). CT scanners are more likely to be found in international airports in North America, Western Europe, and Eastern Asia (e.g., Japan, South Korea, China). Regional airports in the U.S. and international airports in less-developed nations are more likely to still be using X-ray machines. If you're approaching the security area and are confident you see an X-ray machine, you needn't bother asking for a hand check (unless you're using high-speed film, I suppose).

6) Be polite and direct, and speak clearly: "Excuse me sir/ma'am: Could I have a hand-check for some photographic film?" Hold the bag up as you ask the question so he or she can see exactly what you're referring to. If you merely ask the question without displaying the bag, they might mis-hear you and/or be confused about what you're asking, which just increases the chance that they'll deny the request. Confusion almost always leads to suspicion and annoyance, so use words and a visual aid to leave no doubt in their mind about what it is you're asking.

I travel frequently through Denver, Houston, Chicago, Newark, Frankfurt, and London and have never been denied a hand check. I also travel a lot though the Middle East (Kuwait, Oman, UAE, Saudi Arabia) and have yet to see a CT scanner at their airports. There are sometimes differences between the screening technology being used in one part of an airport versus another (e.g., security checkpoints for passengers going landside -> airside, versus security checkpoints for passengers transiting airside only), but if you stick to the above guidelines, you'll likely breeze through without a problem.

Bottom line: Make it easy on yourself. Only ask for hand-check when you see a CT scanner. If it's an X-ray machine, just send the film through and don't give it a second thought.

Arthurwg said:

For sure the best solution.

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I have to say I "hard disagree" on that.

The best solution is to do what we can to raise awareness of photographic film and it's ability to be damaged by the new CT scanners, and thus have hand inspection of photosensitive materials standard across all civil airports in all countries.

Eg, the UK's Department for Transport....when I contacted them a couple of years ago they got back to me in writing to say they had been made aware of the work done by Ilford and Kodak and had instructed all UK civil airports to action requests for hand inspection of films. And the result? Airports such as Heathrow, previously known as a "no hand inspection under any circumstances" airport will now happily hand inspect your films.

The more people who contact airports in advance of planned travel to ask about film, the more people who request hand inspection...the more aware staff will be.

We do also need to bear in mind that the CT scanners will benefit the 90+ % of travellers who don't have film. They won't have to take their liquids and tablets/laptops out of their bags. We are the minority here who will be inconvenienced, but we've already seen increased awareness. My last trip to the USA, all the airports involved had electronic signs pointing out whether the scanners were safe for film.

THe film community *is* making a difference here. There's no need to panic and decide never to fly with film again.

Traveling to Greece every year from the USA while requesting hand checks only results in one conventional X-ray (on the return trip). Buying film on location would cost more, poorer selection, take time. I probably do more damage from the hot temperatures.

Agulliver said:

I have to say I "hard disagree" on that.

The best solution is to do what we can to raise awareness of photographic film and it's ability to be damaged by the new CT scanners, and thus have hand inspection of photosensitive materials standard across all civil airports in all countries.

Eg, the UK's Department for Transport....when I contacted them a couple of years ago they got back to me in writing to say they had been made aware of the work done by Ilford and Kodak and had instructed all UK civil airports to action requests for hand inspection of films. And the result? Airports such as Heathrow, previously known as a "no hand inspection under any circumstances" airport will now happily hand inspect your films.

The more people who contact airports in advance of planned travel to ask about film, the more people who request hand inspection...the more aware staff will be.

We do also need to bear in mind that the CT scanners will benefit the 90+ % of travellers who don't have film. They won't have to take their liquids and tablets/laptops out of their bags. We are the minority here who will be inconvenienced, but we've already seen increased awareness. My last trip to the USA, all the airports involved had electronic signs pointing out whether the scanners were safe for film.

THe film community *is* making a difference here. There's no need to panic and decide never to fly with film again.

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Thank you.... I agree. Arthurwg's solution is really several solutions. Buy film in country/process or have it processed before flying home/ship it home/go digital. For many of us changing from film to digital is not a desired option. Not disputing anything about the quality or value of digital photography. We don't want to change the medium we work in. The acoustic guitarist doesn't want to buy a Telecaster & an amp. The classical violinist doesn't want to plug in and sound like Sammy Kershaw. The sketch artist or oil painter don't want to just take a picture instead. As M McLuhan said "the medium is the message"...... i.e. it's not only the image outcome but the medium that presents it. There...soapbox rant done for today. Travel with film if it's your thing....it not, carry on.