Archived posting to the Leica Users Group, 2000/07/12
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]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 > > > -------------------------------------------------------- > See my photo pages at http://members.xoom.com/cyberplace > -------------------------------------------------------- > t h i n k d i f f e r e n t a p p l e c o m p u t e r > -------------------------------------------------------- > <<< PGP public key available on request >>> > >