Re: Travelers: New X-ray machines WILL ruin your film
Quote:
Originally Posted by
Bob Salomon
Since Congress doesn’t seem to do much why don’t you ask your Representative and your Senators to find the answer?
Politicians don’t listen to me; there is no political issue here to solve. Besides, I’d like a credible answer. If all I wanted was smoke blown up my skirt I’d read some of the inane posts in this this thread. :)
It’s purely an engineering question for which nobody has data to support or refute assumptions and fears.
As you well know, back in the days before film became a niche item there was a consortium that did testing that was the basis of TSA and film company recommendations regarding film safety at airport x-ray inspection.
Nobody cares any more...
Re: Travelers: New X-ray machines WILL ruin your film
Quote:
Originally Posted by
BrianShaw
Politicians don’t listen to me; there is no political issue here to solve. Besides, I’d like a credible answer. If all I wanted was smoke blown up my skirt I’d read some of the inane posts in this this thread. :)
It’s purely an engineering question for which nobody has data to support or refute assumptions and fears.
As you well know, back in the days before film became a niche item there was a consortium that did testing that was the basis of TSA and film company recommendations regarding film safety at airport x-ray inspection.
Nobody cares any more...
They can get the information you want divulged. But you could also ask PMA or NPPA or ASMP or even Nat Geo or a large news paper.
Re: Travelers: New X-ray machines WILL ruin your film
Sorry Bob, but I doubt it...
Re: Travelers: New X-ray machines WILL ruin your film
Quote:
Originally Posted by
BrianShaw
Sorry Bob, but I doubt it...
Then you should try it as you aren’t getting an answer here.
Re: Travelers: New X-ray machines WILL ruin your film
The data probably doesn’t exist on those exact machines... no matter who is asked. Why would anyone bother figuring out if film is vulnerable to CT since it’s already well understood. Right now I’m still busy working for a living to pay for a family. But maybe when I retire I’ll crowdfund an effort to actually measure the impact of these new CT machines. I have more than just a passing knowledge of the past efforts. But I don’t work cheap so the funding will have to be generous!
Re: Travelers: New X-ray machines WILL ruin your film
Okay, my point is that if it screws up light meters-what does it do to digital sensors in cameras?
Re: Travelers: New X-ray machines WILL ruin your film
There's not been any evidence posted that it affects light meters. That was brought up in post #19, but the poster did not offer any reason for being concerned that the X-ray machine would affect silicon photodiodes. He contacted the TSA, and the TSA response was basically "we can't assure you that it won't affect light meters." I can't blame them for that. I haven't seen one of these machines or passed anything through it yet.
In general, I believe the semiconductor junction of a typical SPD light meter is larger than an individual pixel of a CCD or CMOS sensor (which are a few microns), and size typically makes a semiconductor more tolerant to individual faults such as radiation damage. If the X-ray machine were harmful to light meters, it would likely be destroying digital cameras left and right, and probably cellphones, computers, and other silicon devices.
The light-sensitive reaction is different for film versus electrical sensors (CdS meter cells, SPDs, CCDs, etc) and so even if a X-ray machine exposes film, it doesn't necessarily follow that it damages electrical/electronic light sensitive devices. I can't assure you that it's safe, I'm just not worried about that aspect of it.
Re: Travelers: New X-ray machines WILL ruin your film
I think the Light Meter comment was a confusion with 2 languages
Perhaps the OP meant emulsion sensitivity
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Re: Travelers: New X-ray machines WILL ruin your film
Here is some real life experience with one of the new scanners. I was traveling back from Germany to the US through Amsterdam and got an additional security check going from the EU flight section to the international one there. They had one of the new carry-on CT scanners, this one a “ClearScan” by L3Harris, here is a link: https://www.sds.l3t.com/aviation-che.../ClearScan.htm. It looks a bit different than the Analogic machine shown in the article mentioned above, but it is essentially the same thing. I had a bunch of 120 roll film with me and asked for a hand inspection, which they fortunately did. However, anticipating I might encounter a CT scanner on this trip, I left one roll of T-Max 400 in my carry-on. That roll had some blank frames plus some frames exposed to approximately Zones 1-3 on it. I just developed it plus a similar roll that had not seen the scanner, shown side by side on the light table in the attached image - the regular roll on the left, the scanned one on the right. The new scanner fogged the whole film, unevenly, with some repeating pattern visible. The fogging is a bit weaker on the inside of the roll due to the shielding by the outside film layers. Measuring the additional density over the film base + fog of the regular film results in additional values of 0.53 -0.59 for the end of the roll (i.e. the outside) and 0.46 - 0.53 at the start of the roll ( the inside of the exposed roll). In short, any film going through one of those machines will be rendered unusable.
Re: Travelers: New X-ray machines WILL ruin your film
Quote:
Originally Posted by
arne croell
...however, anticipating i might encounter a ct scanner on this trip, i left one roll of t-max 400 in my carry-on. That roll had some blank frames plus some frames exposed to approximately zones 1-3 on it. I just developed it plus a similar roll that had not seen the scanner, shown side by side on the light table in the attached image - the regular roll on the left, the scanned one on the right. The new scanner fogged the whole film, unevenly, with some repeating pattern visible...
yikes !!!!