X-ray effect on unexposed 400ASA( will be pushed to 1600)

[Carljoel]

Hello! I am planning to order Ilford HP5 Plus Black and White Negative Film (35mm Roll Film, 100' Roll) from America to Hong Kong. I will push the film to 1600 after I exposed them. Should I be worried about the X-ray fog problem for the baggage? Please share ur experience with me if you did something similar. Thanks!

 

[railwayman3]

There is a huge amount of postings here and elsewhere regarding the effect of X-ray problems with film in aircraft baggage and in the mail, with no definitive conclusion, other than, in general, it does not seem a major problem.

Personally, I have bought mail-order film (including fast film) from Hong Kong, Europe and Thailand, and passed through numerous airport Xrays with no issues at all. Logically, I doubt the volume of mail would allow any postal authority to Xray every item, and Customs would be more likely to "pass" any parcel which carried a proper contents declaration from an obviously legitimate mail-order supplier. (If any doubts of illegal contents, they would be more likely to open the packet for visual inspection.)

On the rare occasions I have bought items for business from abroad, duty/tax has sometimes been charged on the contents per the declaration, without the parcel being opened (and, of course, I expected this extra and "costed" it into the price.)

I have never had any problems in sending films abroad for processing (particularly Kodachrome in its last year), other than one Orwochrome film some years ago which seemed to show Xray damage, but this was well outdated and of unknown provenance before it was given to me.

 

[Carljoel]

There is a huge amount of postings here and elsewhere regarding the effect of X-ray problems with....... it was given to me.

Thank you! It is good to hear you bought films from Hong Kong. Nearly everyone on the internet said it was not wise to put films in the checked luggage. I don't want to risk 110USD to test the feasibility of the shipping method. I really need to have some reassurance for this purchase. I shall update the status of the film here when I develop a roll of it.

 

[MartinP]

To clarify what you are asking - is the film going to be sent by post, or carried in your checked baggage?

If you carry any photographic material in checked baggage then it is likely to be damaged.

A film with ISO400 does not get any more sensitive if you increase the processing time, so the hand-luggage scanners (commonly described as being 'safe' up to ISO400) would probably not be a problem.

Postal packets seem to be scanned on a sample basis, purely because of the huge volume. Whether any distinction is made for packages listing photographic-materials as the contents is unknown.

 

[Nathan King]

I have had experience traveling with Tri-X and TMax films. I always request hand inspections but, unlike domestic airport security, overseas airports often refuse. I have never experienced damage from the carry-on luggage scanners. The large machines that inspect checked baggage WILL damage the film.

 

[Nathan King]

I have an old issue of Photo District News magazine where they tested X-ray effects on film. Both 35mm and 120 were tested. A worst case scenario was created where the felt opening of the 35mm canisters were pointed at the output source. 400 speed film survived over 12 passes through the machine before any impact on the film was noted.

 

[railwayman3]

Thank you! It is good to hear you bought films from Hong Kong. Nearly everyone on the internet said it was not wise to put films in the checked luggage. I don't want to risk 110USD to test the feasibility of the shipping method. I really need to have some reassurance for this purchase. I shall update the status of the film here when I develop a roll of it.

No, sorry, I didn't make myself clear.......I would NOT risk film in CHECKED luggage in the aircraft hold. But I Have had no problems with film in cabin baggage, or, as I thought you meant, films purchased by post from overseas suppliers.

 

[railwayman3]

hand-luggage[/U] scanners (commonly described as being 'safe' up to ISO400) would probably not be a problem.

Not sure that is quite true? Push-processing to, say, ISO1600 will surely make the film behave as being of that speed and therefore more sensitive? The same exposure (light or Xray) will produce a darker image according to the extent of the "push". The box speed of any film is a nominal guide, the effective speed when in practical use also depends on the development....developer used, time, temperature, agitation, etc.

 

[Colin Corneau]

FWIW -- I took 400 B&W film over to Thailand, multiple airport passes in carryon luggage. I pushed it to EI-800 and then went back through again home, and developed there...no problems.

As for shipping it mail-order, I would ask the vendor but I'd think that if it were a problem they wouldn't be in business long.

 

[Carljoel]

To clarify what you are asking - is the film going to be sent by post, or carried in your checked baggage?

If you carry any photographic material in.........on a sample basis, purely because of the huge volume. Whether any distinction is made for packages listing photographic-materials as the contents is unknown.

I thought the scanning process for checked luggage is equivalent to shipping by post as they are both loaded to the plane in the same way. I am sorry for my misunderstanding.

Not sure that is quite true? Push-processing to, say, ISO1600 will surely make the film behave as being of that speed and therefore more sensitive? The same exposure (light or Xray) will produce a darker image according to the extent of the "push". The box speed of any film is a nominal guide, the effective speed when in practical use also depends on the development....developer used, time, temperature, agitation, etc.

I have the same guess too. 400 ASA should be much more sensitive to light when pushed to 1600. In addition, I couldn't find any forum that discussed what would happen to a 400 pushed to 1600 film under X-ray beams. It is the reasons why I had to make the thread.
To Nathan King, I don't think they pushed the film to 1600. I am confident that using the film at 400 is ok but I have to push the film to 1600 for street photography in Hong Kong.
To Colin Corneau, I can only hope B&H has some way to dodge the X-ray scanning.
I should be able to update the status of the developed film in the end of July. Let's hope for the best.

 

[MattKing]

As pushing doesn't actually increase the sensitivity of negative film, it is not likely that a push development will make the film more susceptible to X-rays.

A push development does increase contrast, so it may make any X-ray damage that does occur slightly easier to see.

 

[RattyMouse]

Hello! I am planning to order Ilford HP5 Plus Black and White Negative Film (35mm Roll Film, 100' Roll) from America to Hong Kong. I will push the film to 1600 after I exposed them. Should I be worried about the X-ray fog problem for the baggage? Please share ur experience with me if you did something similar. Thanks!

You cannot buy HP5 in Hong Kong? I always found film easy to buy there but havent been there in a year or so.

 

[Paul Verizzo]

I always got either a hand check in the old days, or put it in my luggage with a Sima lead bag.

It's my understanding that the X-ray scanners now use far less radiation than when this all started decades ago. Just like your dentist's.

 

[railwayman3]

As pushing doesn't actually increase the sensitivity of negative film, it is not likely that a push development will make the film more susceptible to X-rays.

If it doesn't increase the effective sensitivity, why do we do it ? e.g.

https://en.wikipedia.org/wiki/Push_processing

http://www.the-darkroom.co.uk/cont/push.php

http://motion.kodak.com/motion/support/technical_information/processing_information/push.htm

 

[MattKing]

If it doesn't increase the effective sensitivity, why do we do it ? e.g.

https://en.wikipedia.org/wiki/Push_processing

http://www.the-darkroom.co.uk/cont/push.php

http://motion.kodak.com/motion/support/technical_information/processing_information/push.htm

Exposing film metered at a higher EI than its rated ISO will usually mean that the film is under-exposed.

Push processing will sometimes helps make the results obtained from that under-exposure look more pleasing, even if it doesn't fully correct for the lack of full exposure. Under-exposed negatives lack:

1) detail in the shadows and near shadows; and
2) adequate density and contrast in the near shadows.

Push processing doesn't help with the first part, because the detail lost (due to under-exposure) from the shadows is not recovered, but by increasing over-all contrast, along with the density in the near shadows, the appearance of the near shadows may be improved from muddy and lacking definition to being marginally acceptable.

Of course, there often is a cost as well. In many cases highlight details end up being compressed and distorted.

Push processing can increase sensitivity in reversal materials. The link above to "the-darkroom.co.uk" is in reference to reversal materials.

 

[MartinP]

The pushed film is underexposed (in this case by two stops) and that bottom two stops of shadow detail information is then simply below what the film would have recorded if exposed at the rated ISO. Pushing increases the contrast of the film slightly, or a lot, and among other things this makes it easier to print - that is putting it a bit bluntly, but is about right.

There is also the point that metering is often very imprecise in the sort of scene where many people might want to push their film, for example a night-time street will have massive differences between the electrically lit areas and the shadows so an average meter reading might really be giving you a similar exposure to a grey-card under a streetlight at EI400 - rather than your expected EI1600 !!

Some developers produce a little more film-speed than others and the standard ISO developer is still D76 (ummm, I think?). You can gain some genuine speed by changing developer, but two stops would be a lot more than you would find with mainstream developers. There are some new-ish German developers that can supposedly give more than, for example, Microphen but what the trade-offs might be in terms of contrast or resolution I don't know.

Why do people do it? (Pushing) Ease of handling after under-exposure, and chatter in magazines and internet forums probably

EDIT: It is / was also possible to super-sensitise emulsions by exposure to, and reaction with, various chemical vapours, sometimes heated. This was done in astronomical photography, using special-purpose plates as the medium, and it actually changes the composition of the emulsion. It would not be practical for general purpose use.

 

[railwayman3]

Why do people do it? (Pushing) Ease of handling after under-exposure, and chatter in magazines and internet forums probably

EDIT: It is / was also possible to super-sensitise emulsions by exposure to, and reaction with, various chemical vapours, sometimes heated. This was done in astronomical photography, using special-purpose plates as the medium, and it actually changes the composition of the emulsion. It would not be practical for general purpose use.

Some Ilford cassettes, e.g. HP5+, carry space for you to tick the ISO value used, for processing use, no doubt particularly for their own Ilfordlab service. That's a bit more official than chatter ? Other films, e.g. Ilford's Delta 3200 are designed to accept extended development to attain the maximum speed:

http://www.ilfordphoto.com/products/product.asp?n=10

I am familiar with hypersensitising of film for astrophotography, I actually did it in school days, thanks to an enlightened science master ! I use digital now for astro-work, for once digital really is easier for the amateur. Though I'm sure that analog kits are still available, if not, my grandad used to say that, back in the 1940's a drop of mercury left with the film in a sealed box for a day or two worked wonders.

 

[removed account4]

hi OP

I haven't flown to HK or anywhere besides Europe and the UK with film ( from the U.S. of A )
some film was inadvertantly put in my checked baggage but most of the time it was in
my carry on. many many passes through scanners and X-rays ..
as others have suggested the jury is still out .. but fwiw my film did not get X-ray damage ...
with regards to film sensitivity ( bw film )
i might be wrong, but sensitivity is not variable. it is "set" ... by pushing or pulling it is not changing the sensitivity, but the way the film is processed to develop the latent image recorded on the film.
but in some respects all film has a variable "personal" ISO .. it just depends on the look you want to get from it, processing style
and developing chemistry &c. ( it's kind of like someone suggesting their 135mm on their 35mm is this "normal" lens seeing it is the main lens they might use, and they "see" best with that FL but most people might
say, hey, 50mm is normal for a 35mm ... )
there are mythic ways of increasing sensitivity, like "hypering" the emulsion by steaming it in h2o2
or something like that ( never done it only read about it so I might have gotten the chemical and technique wrong ) ...

have fun with your new film!

 

[railwayman3]

I would maintain that there ia an increase in effective speed with push-processing. The stated ISO rating for any particular film is based on tests using the standard ISO testing methods, and obviously never changes, not even by advertising blurb.

OTOH certain films are designed for push-processing to give a high effective speed.

Some high-speed black-and-white films, such as Ilford Delta 3200, are marketed with film speeds in excess of their true ISO speed as determined using the ISO testing method. For example, the Ilford product is actually an ISO 1000 film, according to its data sheet. The manufacturers do not state that the 3200 number is an ISO rating anywhere on their packaging, merely an "EI" when processed as recommended. Hence the effective speed of this film must increase with push-processing. Kodak and Fuji also marketed E6 films designed for pushing (hence, I imagine, the "P" prefix), such as Ektachrome P800/1600 and Fujichrome P1600; IIRC from when I used the Ektachrome version, the base speed was ISO 400, using standard processing times, but "push" the processing and it certainly, in my experience, behaved as 1600.

 

[wiltw]

There is a huge amount of postings here and elsewhere regarding the effect of X-ray problems with film in aircraft baggage and in the mail, with no definitive conclusion, other than, in general, it does not seem a major problem. .

Kodak OFFICIALLY stated, decades ago, that ordinary film of ISO 400 and below can pass thru multiple passes of airport security X-rays for carry-on luggage without harm but ISO 1600 could be fogged, and should be submitted for hand inspections. Never having flown with anything faster than ISO 400, I can validate what Kodak says about normal speed film. And forget about 'hand inspection' in London's Heathrow airport, they IGNORE ALL such requests!!!
Koday has also OFFICIALLY stated that the CT scanners for CHECKED baggage ALL will harm all films!!!

http://www.kodak.com/global/en/service/tib/tib5201.shtml

edit: Now I note that Kodak's tune HAS CHANGED, on the topic of multiple passes thru scanner with carry-on!:
"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."

 

[railwayman3]

Kodak has OFFICIALLY stated, years ago, that ordinary film of ISO 400 and below can pass thru multiple passes of airport security X-rays for carry-on luggage without harm but ISO 1600 could be fogged, and should be submitted for hand inspections. Never having flown with anything faster than ISO 400, I can validate what Kodak says about normal speed film. And forget about 'hand inspection' in London's Heathrow airport, they IGNORE ALL such requests!!!
Koday has also OFFICIALLY stated that the CT scanners for CHECKED baggage ALL will harm all films!!!

http://www.kodak.com/global/en/service/tib/tib5201.shtml

Thanks, I'd never spotted that ! At least it gives an official statement to counter, or confirm, all the inconclusive chatter.
So no doubt if I later expose my X-rayed HP5+ ISO400 film at an effective speed of 1600 and push-process, it could be fogged.

 

[MattKing]

We are probably just discussing semantics, but "effective speed" is something different than sensitivity.

The films that push well do so because they have a lot of latitude for highlight retention when they are either over-exposed or receive extra development. They don't magically give you detail in the under-exposed shadows. Instead, the near shadows and the mid-tones respond well to the increased development, and therefore yield usable prints.

Remember that the "speed" (actually sensitivity) of film is determined by how it responds to the lowest leveĺs of light in the scene. Push development doesn't effectively change that behaviour, so the speed (actually sensitivity) of the film isn't affected by the push.

As the carry on baggage X-rays are of approximately the same intensity as the light levels that will result in detailed shadows on higher speed (ISO 1600?) film, that film needs to avoid X-rays more than film with a lower ISO, irrespective of what EI was used when metering with the film, and irrespective of whether or not development will be extended.

As I mentioned earlier, the sensitivity of reversal films can be increased with increased development. And the increase in contrast that comes with a push development of negative film may make any X-ray damage that does occur appear slightly more obvious.