Airport and Building X-Ray machines and Digital Cameras

Archived from groups: rec.photo.digital (More info?)

winhag@yahoo.com wrote:
> Folks,
>
> Recently, a friend took her Canon 20D into a building with high
> security. She was forced to put it through their X-ray machines.
> There did not seem to be any ill effects, but in general, can this
> damage the camera/sensor or memory card?


No problem. It takes a lot more than security X-ray and metal detecting
devices to damage them.

--
Joseph Meehan

Dia duit

Archived from groups: rec.photo.digital (More info?)

winhag@yahoo.com wrote:

> [...]

Was google broken when you posted? Because when you go to google,
click on 'groups' and enter 'x-ray security digital camera', you obtain
an answer to your question in about as much time as it takes to type
it.

Archived from groups: rec.photo.digital (More info?)

<eawckyegcy@yahoo.com> wrote in message
news:1126634609.929137.284840@g49g2000cwa.googlegroups.com...
> winhag@yahoo.com wrote:
>
>> [...]
>
> Was google broken when you posted? Because when you go to google,
> click on 'groups' and enter 'x-ray security digital camera', you obtain
> an answer to your question in about as much time as it takes to type
> it.

Why did you bother to respond when the post had already been answered?

Archived from groups: rec.photo.digital (More info?)

Thanks for the answers, and I will use Google first next time!

Archived from groups: rec.photo.digital (More info?)

Pete D wrote:

> Why did you bother to respond when the post had already been answered?

Why did you bother to respond when the post had already been answered?

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<eawckyegcy@yahoo.com> wrote in message
news:1126649334.215374.297200@g43g2000cwa.googlegroups.com...
> Pete D wrote:
>
>> Good answer Martin and much funnier than the Google answer, thats why
>> people
>> come here first, oh yes and because they are not experts at this internet
>> thng like you.
>
> If you want to answer the same question again and again and again, why
> haven't you? Why criticize those who are teaching people to use
> google, and thus becoming an "expert"? Why don't you take your kooky
> form of co-dependence and shove it?
>
Maybe if you presented your "help" in am more helpful and less arrogant
manner people would be mere receptive.

Archived from groups: rec.photo.digital (More info?)

winhag@yahoo.com wrote:
> Folks,
>
> Recently, a friend took her Canon 20D into a building with high
> security. She was forced to put it through their X-ray machines. There
> did not seem to be any ill effects, but in general, can this damage the
> camera/sensor or memory card?
>
NO.


--
Ron Hunter rphunter@charter.net

Archived from groups: rec.photo.digital (More info?)

Jeff wrote:

> Maybe if you presented your "help" in am more helpful and less arrogant
> manner people would be mere receptive.

As far as I can see, the OP, a certain winhag@yahoo.com, received the
message.

What is your complaint?

Archived from groups: rec.photo.digital (More info?)

eawckyegcy@yahoo.com wrote:

> Roger N. Clark (change username to rnclark) wrote:
>
>
>>To all those who say NO to x-ray hurting cameras, you are wrong.
>>
>>Radiation damage is well established in the spacecraft world, where
>>one typically has to use expensive radiation tolerant components.
>>X-rays do damage electronic components, but usually the effect
>>would be small in the case of airport scanners and consumer
>>cameras.
>
>
> How many trips through an airport scanner would a camera have to take
> to equal, say, an hour in low earth orbit? A trip through the Van
> Allen belts? A cruise to Mars, blasted every month or so by another
> CME?
>
That is a good question. A rough idea goes as follows:
We take images with systems in Earth orbit, cruising
around the solar system, and orbiting other planets.
For the most part the images are clean with occasional
cosmic ray spikes in the data. But I bet if you tried to
take a picture in an X-ray machine, the x-rays would
totally over expose the image. One could try this by
setting the camera to say 30 second exposure and tripping
the shutter just as you put the camera on the belt going
into the machine.

Orbiting Jupiter is a much higher radiation environment and
the Galileo spacecraft instruments basically stopped working
after a few years, and that is with radiation tolerant
electronics.

Cassini was launched in 1997 and has suffered no apparent
damage from radiation so far orbiting Saturn.
Both the ISS camera and VIMS are doing very well.
Noise levels are unaffected so far.

Roger

Archived from groups: rec.photo.digital (More info?)

Wait a second here.

CCD's respond to visible and near visible light, aka, photons, also known as
non-ionizing radiation.

X-Ray's do not contain photons, so a CCD would not respond at all. X-Ray's
are known as ionizing radiation.

Now in an Digital X-Ray system, in order to be able to visualize what the
X-Rays are penetrating, you need an intermediary between the course of the
X-Rays and the CCD. This is a fluorescent material of some kind, that when
X-Rays strike the material, the material in turns emits photons that the CCD
can pick up.

The lifetime of these extremely physically large CCD sensors is in fact
several years or more and thus it is unlikely X-Rays would in fact damage a
CCD Sensor, even over many exposures over time.

Systems that emit X-Ray radiation for medical purposes do not splash X-Rays
all over the place. If they did, you'd be exposing the folks on the floor
above and below and beside the treatment room. They emit a constrained beam
of X-Rays at the diagnostic area.

http://www.canon.com/technology/in [...] ay_p4.html


"Roger N. Clark (change username to rnclark)" <username@qwest.net> wrote in
message news:43290406.7010408@qwest.net...
> eawckyegcy@yahoo.com wrote:
>
> > Roger N. Clark (change username to rnclark) wrote:
> >
> >
> >>To all those who say NO to x-ray hurting cameras, you are wrong.
> >>
> >>Radiation damage is well established in the spacecraft world, where
> >>one typically has to use expensive radiation tolerant components.
> >>X-rays do damage electronic components, but usually the effect
> >>would be small in the case of airport scanners and consumer
> >>cameras.
> >
> >
> > How many trips through an airport scanner would a camera have to take
> > to equal, say, an hour in low earth orbit? A trip through the Van
> > Allen belts? A cruise to Mars, blasted every month or so by another
> > CME?
> >
> That is a good question. A rough idea goes as follows:
> We take images with systems in Earth orbit, cruising
> around the solar system, and orbiting other planets.
> For the most part the images are clean with occasional
> cosmic ray spikes in the data. But I bet if you tried to
> take a picture in an X-ray machine, the x-rays would
> totally over expose the image. One could try this by
> setting the camera to say 30 second exposure and tripping
> the shutter just as you put the camera on the belt going
> into the machine.
>
> Orbiting Jupiter is a much higher radiation environment and
> the Galileo spacecraft instruments basically stopped working
> after a few years, and that is with radiation tolerant
> electronics.
>
> Cassini was launched in 1997 and has suffered no apparent
> damage from radiation so far orbiting Saturn.
> Both the ISS camera and VIMS are doing very well.
> Noise levels are unaffected so far.
>
> Roger

Archived from groups: rec.photo.digital (More info?)

Roger N. Clark (change username to rnclark) wrote:

> ... But the original
> hospital X-ray machine should not have had x-rays leaking out,
> or did you put it in the machine?

The X-ray machine in this case was not a diagnostic machine
but a treatment machine. It puts out very much higher energy
X-rays than are used for diagnostics in order to damage the
nuclei of cancer cells in such a way that they are unable
to divide and reproduce.

The patient lies on a table and the machine rotates around
and underneath him, shooting rays from different angles and
with different focal lengths and apertures in order to
deliver the maximum dosage to the tumor and the minimum
dosage to healthy tissue around it. The idea is that, by
focusing on the tumor and moving the emitter, the entry and
exit beams pass through different parts of the body giving
each a relatively low dose, while the tumor at the focal
point gets the full dose no matter what angle the emitter
is at.

Unfortunately, my briefcase with the camera inside was off
to one side of the table and must have gotten zapped when
the X-ray emitter was aiming from the other side of the table.

The entire treatment room is lead shielded to protect the
rest of the hospital.

To answer Richard's questions:

The CCD was NOT damaged. The camera continues to take pictures
with no problem. But the LCD display on the back no longer
works. This means I've got no menus and can't do anything
with the camera that requires them. Fortunately, the camera
has an optical viewfinder, so I can still take photos - albeit
with much restricted controls.

Alan

Archived from groups: rec.photo.digital (More info?)

Alan Meyer wrote:

> Roger N. Clark (change username to rnclark) wrote:
>
> > ... But the original
> > hospital X-ray machine should not have had x-rays leaking out,
> > or did you put it in the machine?
>
> The X-ray machine in this case was not a diagnostic machine
> but a treatment machine. It puts out very much higher energy
> X-rays than are used for diagnostics in order to damage the
> nuclei of cancer cells in such a way that they are unable
> to divide and reproduce.

http://en.wikipedia.org/wiki/Radiotherapy

These fluxes are high; an airport scanner's flux is probably two or
three orders of magnitude weaker than these. Do the technicians warn
you about things you may take into the room?

Archived from groups: rec.photo.digital (More info?)

Richard Tomkins wrote:
> Wait a second here.
>
> CCD's respond to visible and near visible light, aka, photons, also known as
> non-ionizing radiation.
>
> X-Ray's do not contain photons, so a CCD would not respond at all. X-Ray's
> are known as ionizing radiation.

X-RAYS ARE PHOTONS!

Try a google search with: CCD X-ray damage
You will see many entries.

Examples:
http://www-cr.scphys.kyoto-u.ac.jp [...] Damage.pdf

http://www.iop.org/EJ/abstract/0031-9155/44/4/022
Contrast reduction in digital images due to
x-ray induced damage to a TV camera's CCD image receptor

A google search finds:
http://hps.org/publicinformation/ate/q549.html
Health Physics Society: Category: Radiation Effects — Effects on Animals
"Inspectors in California have taken several radiation measurements
at conveyors in Los Angeles and Burbank airports, and other
regulators have checked similar x-ray security devices installed
in workplaces. The results were similar—radiation exposures were
on the order of 0.15-0.17 millirad per bag or per exposure."

The 1999 www.iop.org article above cites permanent CCD damage observed in
images at less than 20 Rads. 20/0.0015 ~ 15,000 exposures. However,
cameras have improved a lot since that 1999 study, now being photon
noise limited at their rated quantum efficiencies, thus much smaller
doses could effect performance. We need more recent studies.

Roger
>
> Now in an Digital X-Ray system, in order to be able to visualize what the
> X-Rays are penetrating, you need an intermediary between the course of the
> X-Rays and the CCD. This is a fluorescent material of some kind, that when
> X-Rays strike the material, the material in turns emits photons that the CCD
> can pick up.
>
> The lifetime of these extremely physically large CCD sensors is in fact
> several years or more and thus it is unlikely X-Rays would in fact damage a
> CCD Sensor, even over many exposures over time.
>
> Systems that emit X-Ray radiation for medical purposes do not splash X-Rays
> all over the place. If they did, you'd be exposing the folks on the floor
> above and below and beside the treatment room. They emit a constrained beam
> of X-Rays at the diagnostic area.
>
> http://www.canon.com/technology/in [...] ay_p4.html

Archived from groups: rec.photo.digital (More info?)

"Alan Meyer" <ameyer2@yahoo.com> wrote in message
news:1126824637.433411.127920@g43g2000cwa.googlegroups.com...
SNIP
> Has anyone tried any of the lead lined bags for cameras
> and film? See for example:
>
> http://www.herringtoncatalog.com/p105.html
>
> Do they actually provide significant protection?

To normal or high altitude background radiation, yes they help.

> Will the airport inspectors allow them through or do they
> just pull them out and put your cameras through the machine
> without them?

No, they'll just increase the X-ray output till they can see through
the obstruction. If that fails, they'll presumably hand inspect what's
left ;-)

Bart

Archived from groups: rec.photo.digital (More info?)

On Thu, 15 Sep 2005 12:27:43 -0400, "Richard Tomkins"
<tomkinsr@istop.com> wrote:

>Wait a second here.
>
>CCD's respond to visible and near visible light, aka, photons, also known as
>non-ionizing radiation.
>
>X-Ray's do not contain photons, so a CCD would not respond at all. X-Ray's
>are known as ionizing radiation.

I await the massive reorganization of physics based on your
new insight.

Apparently the fogging of film was also caused by the
non-photons of x-rays.