Film Shield Bags

I just returned from a month in NZ and took 35mm casettes and 120

rollfilm. On the way down there I asked for and got hand inspections

because I was told by various camera store peeps that if you use the

lead bags they crank up the x-ray machine etc etc. So, on the way back

having had no x-rays going I decided to test this and just left the

film in the lead bags on the upper part of my carry-on luggage. No

problemos...the bag went through at the same rate as the others, no

crank ups no nothing. So, there are some old wives tales, imho, that

have been laid to rest. But I am not sure I feel a whole lot safer as

a traveler. Hmmmmm.

Scanner operators can not crank up the juice. What you see on the monitor when they are thinking about your funny stuff is contrast adjustments.

This upping the gain to look through a lead lined bag sounds a bit like an urban myth. Are there any security machine operators or manufacturers on Photo.net who could confirm or deny it? It seems to me that the power would be set to a pre-determined level and left there. It is not hospital radiology, after all.

So, Omelette, you did the right thing all by yourself.

 

in my travels, film always garnered suspicion, but once I started relying on the lead bag, i have not been stopped, searched even once.

 

Incidentally, on long (and thereby high altitude) flights, the radiation from space contributes about equally as the x-ray machines do. And a lead bag does wonders.

 

Funny name you handle yourself by. Though ...

It's always good to know *what* old wives' tale you're laying to rest.<BR>The way I heard it, you use a lead lined bag when putting film in your *checked* luggage, which is scanned much harder. If the machine sees a lead-lined-lump then they'll crank up the juice, rendering your lead-lined bag useless. If you use the thicker lining, they'll just halt the whole process and hand-search it.

<BR><BR>

Anyway, a lead lined bag isn't needed for carry-on scanners. I've tried taking some rolls through multiple airports; I wish I had the time to find the negs... Unexposed Superia 1600 ended up with two purple blobs on two frames, but that's inconclusive.

I believe Cole's right, it's only with checked baggage that they turn up the heat if they can't easily see through something. That's when the lead bag thing doesn't work. An it's true that they will do hand searches of anything suspicious or can't be penetrated with their ray guns. With hand carry bags, if they are suspicious they just hand search.

 

Also, not all airports have the newer high powered units for checked bag lines. And most airports that do have them, don't have enough to check all the bags with them. You may have just gotten lucky.

I strongly suspect that if they "turned up the heat" to see thru a double lead-lined bag that they would be throwing so much radiation out that their own shields would leak. They would toast their tosies!

I SUSPECT that operators can't turn up the dose on

hand-baggage machines. I mean how could these machines

display notices to the effect that they're film safe if someone with

a twitchy finger could make a nonsense of that.

 

But I don't know for certain.

 

Can we have a contribution from someone that actually knows

please. Then I'll know for certain that there is absolutely no point

buying lead bags or any other form of shield and that the people

who make and sell these things are just exploiting irrational

fears and gullibility.

"on long (and thereby high altitude) flights, the radiation from space contributes about equally as the x-ray machines do."

 

HUH? I've never heard that before. What is the scientific source of this? If true, does that mean that getting my 60 rolls of Velvia 100F hand-inspected means nothing on a 10 hour flight to eastern Europe because it's just going to the same amount of radiation while in-flight?

 

Cancer rates amougst frequent flyers would be higher too, right?

The operator can reverse the conveyor belt and send the lead-lined item back for a closer look, and can let it "sit" under the beam longer. I've tried the bags but how do you get 5 bricks of e-100-g in them?

<i>"people who make and sell these things are just exploiting irrational fears and gullibility."</i>

<p>Nuthin' new 'bout that. Remember the post-9/11 gas mask boom?

lets see here ... amp up the x-rays , ummmm no u cant do that ... if u go any higher u would be going into gamma rays ... and yes they adjust the contrast of the picture ... u camarea geniuses should noe there are negatives to pictures too and they can reveal wht the normal eye would miss ... ok the other thing is lead is non-ferrous and also into classification as a anti-ferrous therefore blocking magnetic field and radiowaves, light waves, gamma , x-ray ,uv ... so forth double shielded bags dosent do S#!t the x-rays will not penetrate the bag anyway cuz thats the whole point of lead and doubling the power lol ... and fuckin rays on a flight what the hell are u talking what do u think the atmosphere is 4 idiot and the magnetic field ... im kinda feelin smart for only being 14 ... im sry if im wrong but i learned this from my 26 yr old chemistry teacher i dont learn much cuz im constantly bombarded by gamma rays that kill all my bad brain cells for talking to much to retards ... im just gonna shut up cuz that made no sense go have a wonderfull fuckin time taking pictures off naked ppl ... ooops this isnt a porn site my bad ;(

"on long (and thereby high altitude) flights, the radiation from space contributes about equally as the x-ray machines do."

 

HUH? I've never heard that before. What is the scientific source of this? If true, does that mean that getting my 60 rolls of Velvia 100F hand-inspected means nothing on a 10 hour flight to eastern Europe because it's just going to the same amount of radiation while in-flight?

 

Cancer rates amougst frequent flyers would be higher too, right?

 

This is absolutely true. My life was spent in the radar business which is all about ionizing radiation so I know quite a bit about this. Of all career fields airline pilots receive more ionizIng radiation annually than all other relevant career fields, e.g., nuclear power plant workers, dental technicians, etc. I have taken a Geiger counter up with me countless times and the higher in altitude you go, the more ionizing radiation you get! Trip across the pond? Figure it's like an extra chest x-ray. Our NASA missions to Mars are challenged right now about having our astronauts survive cosmic radiation over such a long mission. Earth's atmosphere does wonders to protect us from chromosomal mutation.

 

Dan

Hello.

 

Some weeks ago I made an experiment with the X ray machine of a small airport (it seemed like a brand new machine, unlike those old machines with supposedly ultra powerful x ray radiation). After I had passed my luggage with my exposed film in a Film Shield 20 xpf lead bag, I took my rolls out of the lead bag and asked the X-ray machine operator if I could run a small experiment. I was able to do that because 1) the airport was almost empty and 2) the lead bag had created suspicion when I passed through the X-ray machine for the first time. (Since I own the lead bag, it has ALWAYS created suspicions among the x-ray machine operators).

 

So, I grabbed my keys, I threw them into the lead bag and I passed it all through the x-ray machine again... Do you know what happened? I could watch my keys in the x-ray machine screen, inside the lead bag. They were opaque, but the conclusion is that the x-ray machine did could see through the Film Shield 20 xpf lead bag.

 

Second conclusion? The Film Shield 20 xpf lead bag is worthless and, as far as I know, it is one of the thickest lead bags in the market.

You've replied to a discussion that's years old. Nevertheless.....

 

You have to distinguish between gate security x-ray machines and the x-rays for checked luggage.

 

At gate security, there are employees that have to be in the immediate vicinity of the x-ray machines the entire work day, so dose rates from those machines are an important occupational safety issue. The massing of x-ray machines in small areas for gate security after 9/11 created a problem - the old continuous beam x-ray machines required a lot of shielding, and massing those machines meant putting a weight load on a small floor area that was never designed to carry that much weight. The solution was pulsed x-rays.

 

The gate security x-ray machines all over the US, Canada, most of Europe and the major airports of the rest of the world now use a pulsed x-ray beam that fires just like an electronic flash. The detector system below the conveyor belt puts the x-ray image onto the screen the operator watches, allowing the operator to examine the x-ray result. The image acquired is larger than the screen can display, so the operator can move the image back and forth to see all of it, and the belt moves in sync with the image so the operator can identify the location of an item on the belt accurately. The flash of x-rays is so short that the doses to the people who work there all day are unmeasurably small. I know - I measured them.

 

Checked luggage scans are another matter altogether. Airports in the US and major cities around the world now have automated CT scan systems to examine checked bags. Many of the airports do these scans on a random sample of bags, but I know that some in the US airports scan 100% of checked luggage - Las Vegas, Albuquerque, and the airports around Washington, DC. There are undoubtedly others that I am not aware of. The CT scan delivers a film-ruining dose - never put your film in a bag to be checked. The scan results are examined by a computer algorithm that keys on specific patterns in the images and flags bags for further examination (meaning they get opened).

 

As for doses at altitude, your film isn't at risk - the doses aren't high enough unless you spend so much time flying that you'll be broke the rest of your life. Airline flight crews do receive doses in the hundreds of millirem per year, but that not enough to disturb the universe. To give you a sense of scale, the average dose for the US from naturally occurring radiation is 350 millirem per year. But it's double that - 700 millirem per year - in Colorado (all those granite mountains and the high altitude). If an additional 350 millirem above the national average could harm your film, photography in Colorado would be awful. And - and - and - the incidence of cancer in Colorado is lower than the national average - these dose levels aren't enough to bring cancer into play.

 

There are more extreme examples. There's a region in India where the soil doesn't contain silicon-based sand - the sand in that soil is thorium oxide, which is naturally radioactive. The average dose per year in this region is about 1,400 millirem, and comprehensive study of the people living there shows cancer rates comparable to other rural agricultural regions around the world. And there's region in Argentina with the same kind of sand and average doses are around 1,800 millirem per year, and still no elevated incidence of cancer.

 

So, there's no doubt that you get a bit more radiation exposure when you fly, and people who fly for a living get doses higher than typical nuclear power plant workers, but those doses aren't large enough to exceed doses that people on the ground at various places around the world live with every year.

 

As for your lead-lined bag, it's not useless - but, lead is not completely opaque to x-rays. It just dims the brightness of the x-rays. So film in your lead bag will receive less dose than it will riding unprotected in the gate security x-ray machine. But riding unprotected in that gate security machine (i.e., no lead-lined bag) won't cause any visible harm, either. However, your lead bag will be thoroughly inadequate to protect your film in a check bag CT scan.

^ Thanks for that , I've had good luck just getting film hand checked at every airport I've been to . One exception

was in Hanoi where the fellow deemed it necessary to open every every pouch of 120 film ! He didn't take it out

of the wrapper , just tore the top off and looked (luckily there was only 10 rolls for him to play with :) . Peter

Thanks a lot Bob! I'll keep using my lead bags : )

 

I started to worry about X rays after reading an interview of Sebastiao Salgado, in which he said that he was no longer shootting film because gate x-ray machines where damaging his exposed film. Apparently, the fogging was so severe that the images were unusable. "Unsusable" to his standards might be just that the film contrast decreases. Years ago I have been haunted by that...

 

Some time ago I decided to resign and just not worry anymore...

Between high altitude cosmic radiation, and poorly maintained x-ray machines, actual fogging of all but the slowest ISO films occurred on my last trip with film -- which was why it was my LAST trip with film. I'm sure the lead bags do some good, and I still have one in the cupboard. On that same trip when I asked for manual inspection one 'searcher' made me open every single box and film canister so as to "discourage the others"

Ich weiß nicht, was soll es bedeuten, Daß ich so traurig bin, Ein Märchen aus uralten Zeiten, Das kommt mir nicht aus dem Sinn.

Last summer, I had a lead back through US airports. The first trip through the scanner, they saw the lead bag.

 

Then they took the bag out of the suitcase, and ran both, separately, through the machine.

They did not open the lead bag.

 

All US airports that I have been though were good at hand inspection when asked.

Not so for other countries.

https://www.aapm.org/pubs/reports/RPT_217.pdf

 

has dose numbers for backscatter Xray, and also for background and in-flight

radiation levels.

has dose numbers for backscatter Xray, and also for background and in-flight

radiation levels.

 

but for "backscatter" and for after 2007

but for "backscatter" and for after 2007

 

Some might be interested in backscatter, and I don't think ground or in-flight radiation levels

have changed much since 2007.

 

I believe someone commented previously on the in-flight dose for film.