Baggage X-ray Scanning Effects on Film
Contents
Updated April 8, 2003
Airport baggage scanning equipment can jeopardize
your unprocessed film
Because your pictures are important to you, this information
is presented as an alert to travelers carrying unprocessed film.
New FAA-certified (Federal Aviation Administration) explosive
detection systems are being used in
U.S. airports
to scan (x-ray)
checked baggage.
This stronger scanning equipment is also being used in many non-US
airports. The new equipment will fog any unprocessed film that passes
through the scanner.
The recommendations in this document are valid for all film formats
(135, Advanced Photo System [APS], 120/220, sheet
films, 400 ft. rolls, ECN in cans, etc.).
NOTE: X-rays from airport scanners don't
affect digital camera images or film that has already been processed, i.e. film
from which you have received prints, slides, KODAK PHOTO CD
Discs, or KODAK Picture CDs.
This document also does not cover how
mail
sanitization affects film.
Suggestions for avoiding fogged film
X-ray equipment used to inspect
carry-on baggage
uses a very low level of x-radiation that will not cause noticeable
damage to most films. However, baggage that is
checked (loaded
on the planes as cargo) often goes through equipment with higher
energy X rays. Therefore, take these precautions when traveling
with unprocessed film:
-
Don't place single-use cameras
or unprocessed film in any luggage or baggage that will be checked.
This includes cameras that still have film in them.
-
If an attendant or security personnel informs you that
your carry-on baggage must be stowed with the checked luggage or
go through a second scan, remove your unprocessed film.
-
Have your exposed film processed locally before passing
through airport security on your return trip.
-
If you're going to be traveling through multiple
X-ray examinations (more than 5 times), request a hand search of
your carry-on baggage. FAA regulations in the U.S. allow for a hand
search of photographic film and equipment if requested. (See below
for further FAA information.) However, non-US airports may not honor
this request.
-
Request a hand inspection for all motion imaging origination
films. Testing shows fog on motion imaging films even after a single
X-ray scan. This increased fog flattens the entire toe region of
the sensitometric curve reducing shadow detail in a telecine or
projected image. However, Explosive Trace Detection instruments provide
no risk to motion picture films and can be used in conjunction with
hand inspection to provide a non-destructive method of motion film
inspection.
-
If you're asked to step aside for a more thorough
scan of your carry-on baggage, the film could be harmed if they
use the more intense X-ray equipment.You should take your unprocessed
film out of your luggage.
-
Lead-lined bags, available from photo retailers, will weaken
the X-radiation on film and reduce potential harm. However, the
effectiveness of any particular lead bag depends on the intensity
and electric potential of the X-ray generator, the lead's
thickness, and the film speed. If you use a lead bag, check with
the manufacturer for the effectiveness of their products with airport
X-ray devices. The inspection process may be triggered
by a lead bag on the scanner screen. In a typical airport surveillance
situation, the baggage may be pulled aside for additional inspection.
-
Consider shipping unprocessed, unexposed or exposed film
through an expedited carrier, but first check with the carrier to
determine what package examination procedures they are using.
-
Be polite, helpful and patient. Please remember that security
personnel are trying to protect the traveling public.
The Transportation Security Administration (TSA) recommendations
for traveling with film may be found at
www.tsa.gov.
The FAA provides air travelers in the United States the right
to request a non-X-ray inspection of photosensitive products. For
more information, see
www.faa.gov.
Remember that this only applies to air travelers in the United States.
Corrections can't be made at the processing
lab
The processing lab cannot separate X-ray fog from camera exposure,
and because this type of X-ray fog often appears in patterns, it
is impossible to correct this damage in the duplicating or printing
process. Therefore, make every effort to keep your film away from
baggage scanning devices.
The X-ray scanning process
There are two types of higher-dose scanners. The first type is
similar to a hospital CAT scan and uses a low-dose scan followed
by a higher-dose scan on specific areas of the baggage. The second
type gives a high-dose, full bag scan on the first pass, damaging
the film immediately.
Tests indicate that there is significant fogging of unprocessed
film when the film sustains a direct hit by either of the different
scanner's high intensity X-ray beam. Faster films show
a more dense fog.
X-ray fog appearance
Fog caused by the new baggage scanners is usually more pronounced
than fog caused by other means. Fog from the CAT scan type of scanner
typically appears as soft-edged bands 1/4 to 3/8
inch (1 to 1.5 cm) wide. The orientation of the fog stripe depends
on the orientation of the film relative to the X-ray beam.
The banding may be linear or wavy and can run lengthwise or horizontally
on the film. It can also undulate, depending on the combination
of the angle of exposure and the multiple laps of film on the roll.
(See images below.) However, the fog will usually lack the more
subtle patterns produced by traditional types of X-ray
equipment. Additionally, whether or not this stripe is seen in the
photographic print may depend on scene content. Busy scenes with
flowers, foliage, etc. may obscure or lessen the perception of X-ray
effects.
Fog appearance:
-
On black-and-white
negative films - Dark areas in patterns as described above.
-
On color-negative films - Dark
areas with neutral or brown patterns.
-
On color-reversal films (slides) -
Minus-density area (light patches) with patterns as described above.
Fog from the full bag, high-dose scanners affects the whole negative,
causing the entire image to appear overexposed and grainy. Dark
or black images might appear green.
Effects of the CAT scan type scanner on 800 speed film as seen
in a print:
Effects of the Examiner 3DX 6000, full bag scanner, before and
after one scan:
Effects of the Examiner 3DX 6000 full bag scanning equipment
after 5 scans:
Additional comparisons of pictures on 400 speed film that were
exposed to the full bag type of airport scanners:
No scan:
One scan:
No scan:
One scan:
Heavy grain can be seen throughout this image shot on 200 speed
APS film, and a greenish tint appears in some of the dark areas
due to a full bag scanner:
A night photo on KODAK GOLD 200 Film, after one scan on the CAT
scan type scanner:
Photo courtesy of F-STOP, a film advocacy committee.
Samples of unexposed KODAK PROFESSIONAL PORTRA 400VC Film (color-negative)
that have been scanned are shown below and illustrate the appearance
and severity of the exposures.
Print from color-negative film:
Print from color-negative film:
Color-negative film:
Other conditions that resemble x-ray fog
Certain film keeping conditions can produce effects that are
confused with X-ray fog. The older the film, the greater accumulation
of actinic radiation. With time, ambient radiation slowly fogs the
faster silver halide grains so that the film appears grainier. This
is especially noticeable on 800 speed or faster film. Keeping the
film cool or frozen does NOT change this effect. Over time, radiation
can penetrate or occur naturally in nearly all materials.
Heat can affect the film's tone scale and color, giving
results that look like X-ray fog. The amount of damage depends on
the specific film and the storage conditions.
You can usually distinguish the
more common
types of X-ray fog by the distinct patterns and increased
granularity. On 35 mm film, reverse wind streaks are often
mistaken for X-ray fog. However, these streaks are more
evenly spaced and prominent, and tend to bow outward from the film
perforations.
As noted earlier, exposure to some types of airport security
equipment produces pronounced bands of plus density (dark patches)
or minus density (light patches). The fog pattern can resemble typical
white-light fogging that occurs in a defined path, i.e.
from pinhole light leaks in equipment. The most defining characteristics
of fog caused by the CAT scan type of equipment are the well defined
width of the bands and a uniform density, with an increase in granularity
within the band. The banding typically runs continuously through
the whole roll or is broken by patterns from the laps of film in
the roll.
The full bag scanning type of security X-ray equipment causes
a fogged and grainy appearance over an entire picture or over the
entire roll of film.
Motion picture, professional films and special processes
Travelers probably shouldn't worry about possible X-ray
damage when hand-carrying their film onto the airplane unless they
are carrying:
-
Highly sensitive X-ray or scientific
films.
-
Film with an ISO speed or Exposure Index (EI) of 400 or
higher.
-
Any motion picture films.
-
Film of any speed that is exposed to X-ray surveillance
more than 5 times (the effect of X-ray screening is cumulative).
-
Film that is or will be underexposed. (See
Note
1 below.)
-
Film that you intend to "push process." (See
Note 2 below.)
In any of these cases, you should request visual inspection of
your film and of any cameras containing film. Depending on the format(s)
of film you have, carrying a light-tight changing bag may
be advisable to help the inspection process. Remember that this
is only a guaranteed option in U.S. air travel. Outside of the U.S.
you are required to comply with the local standards and regulations.
NOTE 1: X-ray fog is most noticeable
in the low exposure range of the film, and underexposed film has
more of the image recorded in this range. Therefore, the effects
of X-ray exposure may further reduce the quality of underexposed
images.
NOTE 2: Push-processing involves over-development
of film to increase the effective speed and density of underexposed
images on color-negative and black-and-white films. On color-reversal
films (slides), push-processing on underexposed images decreases
the density range. X-ray exposure has the potential to
degrade the quality of images that will be push processed.
See
more information on how to protect motion picture films
from X-ray fog or mail sanitization.
Samples of unexposed KODAK VISION 200T and 320T Color Negative
Film scanned by a checked-luggage scanner are shown below to illustrate
the appearance and severity of X-ray fog.
Below are samples of KODAK VISION 320T Color Negative Film (16
mm motion-picture film) exposed to an INVISION CTX-5500 baggage
scanner.
Advice to professional photographers and cinematographers
Kodak suggests taking the following precautions when transporting
film via the airlines:
-
Never ship unprocessed film as
checked luggage with commercial airlines. Keep
all unprocessed film as carry-on baggage.
-
If you plan to hand-carry unprocessed film on an airplane
at an international airport, contact the airport security office
before your flight and ask if they will conduct a manual inspection.
-
Bring a light-tight changing bag.
-
Be cautious with film not purchased through Kodak or authorized
Kodak dealers. Ask about the source of the film, and consider shooting
a test before you use it.
-
Lead-lined bags, available from photo retailers, weaken
the X-radiation on film and reduce potential harm. However, the
effectiveness of any particular lead bag depends on the intensity
and electric potential of the X-ray generator, the lead's
thickness, and the film speed. If you use a lead bag, check with
the manufacturer for the effectiveness of their products with airport
X-ray devices. The inspection process may be triggered
by a lead bag on the scanner screen. In a typical airport surveillance
situation, the baggage may be pulled aside for additional inspection.
Who to contact
Call Kodak if you need additional help:
-
For consumer film products, call 1-800-242-2424
(US only) or see the
Worldwide Contact page.
-
For motion picture products, call 1-800-621-3456 (FILM).
Kodak, Kodak Professional, Gold, Photo CD, Portra, and
Vision are trademarks of Eastman Kodak Company.
TIB5201
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