Archived posting to the Leica Users Group, 2000/07/12

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Subject: RE: [Leica] Airport X-rays and film inspection
From: "B. D. Colen" <bdcolen@earthlink.net>
Date: Wed, 12 Jul 2000 12:11:01 -0400

FYI - I haven't done this in a while, but I have found that taking the film
out of the little canisters, and putting the cassetts in ziplock plastic
bags, facilitates hand inspection.....


> -----Original Message-----
> From: owner-leica-users@mejac.palo-alto.ca.us
> [mailto:owner-leica-users@mejac.palo-alto.ca.us]On Behalf Of Pascal
> Sent: Wednesday, July 12, 2000 11:18 AM
> To: LEG; LUG
> Subject: [Leica] Airport X-rays and film inspection
>
>
> On 24-06-2000 14:44 Brad Farr wrote:
>
> >For those of us without ready access to CDI, what the bottom line?
> >Keep the film out of the scanner and insist on inspection by hand?
>
> The new systems for checked-in (not carry on) baggage, CTX-5000, CTX-5500
> and L3 scanners, are a disaster for your films because of their high
> energy (180 kV), and this regardless of the film speed and whether the
> films have been exposed or not.
> These tests were conducted by Pima (association of photo products
> manufacturers) and InVision Technologies, maker of the new scanners. The
> comparison pictures in CDI speak for themselves, already after one run
> through the system the film gets fogged, especially with the L3 type of
> scanner (this one is very effective: it scans a piece of baggage with a
> rotating X ray tube (90 cycles per minute).
> The "advantage", if one can use this word, of the L3 scanner is that the
> whole film surface gets evenly fogged, in contrast to the CTX scanners
> where fogging will happen in stripes and uneven zones (because the latter
> scanners don't have a rotating tube).
> The effect of one single check by either one of those new scanners is
> that your film gets a + 1 EV exposure (of course, multiplied each time
> the baggage gets another check).
>
> Hence, the only way to avoid this is to put all films and cameras with
> loaded film in carry-on hand baggage. Only the X-ray machines for hand
> baggage is acceptable and harmless for films, at least, for films of
> medium sensitivity (maximum 1600 ASA). However, each passing through an
> X-ray machine for hand baggage, multiplies the X-ray exposure. The
> maximum number of successive exposures to such X-rays is 5 times, before
> effects may become visible. So, after 4 successive X-ray checks, a manual
> inspection should thus be demanded.
>
> Another word of caution: lead bags for films will oblige the X-ray
> machine operator to increase the power of the machine in order to see
> through the bag. This will, of course, result in even more X-ray emission
> which is more detrimental to your films than if you had just put them in
> your hand bagage without lead bag.
>
> On the other hand, and this is my personal experience, the latest Sigma
> lead bag Film Shield 20 XPF has been made especially against high-dose
> X-ray scanners (for hand baggage). It is *impossible* to see through it
> with machines for inspection of hand baggage, whether the dose is
> increased or not. And this I have witnessed myself. The result of this
> is, however, that, in most cases, you will be taken aside for a manual
> inspection of your hand baggage as they will have found something
> "suspect" in your bag. Be warned that this is not a light-weight solution.
> So, the advice of CDI not to use lead bags may be valid for most bags,
> but certainly not this one.
>
> Pascal
> NO ARCHIVE
>
>
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Replies: Reply from "RP Johnson" <rpjohnson2@home.com> (Re: [Leica] Airport X-rays and film inspection)
Reply from Ted Grant <tedgrant@home.com> (Re: [Leica] Airport X-rays and film inspection)