Furthermore, in the past when I have used Kodak HIE, I just loaded the camera in very dim light. I have not yet tried the IR820, but I just got some and plan to shoot it soon.
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If you are saying that loading Kodak HIE in dim light gave you no problems with fogging then if I have understood the relative sensitivities of each film correctly, you have answered your own question. Namely if Kodak HIE is OK in dim light then Efke Aura 820 should be as well.
The prevailing wisdom is that you ought to have had problems with Kodak in anything other than total darkness but you seemed to have proved this to be wrong.
We make many assumptions based on what we are told and accept the wisdom without I suspect checking out the assumption we are given.
pentaxuser
If you are saying that loading Kodak HIE in dim light gave you no problems with fogging then if I have understood the relative sensitivities of each film correctly, you have answered your own question. Namely if Kodak HIE is OK in dim light then Efke Aura 820 should be as well.
pentaxuser
Personally, I am not convinced that the susceptibility to fogging has to do with the wavelength so much as the fact that the polyester substrate acts as light pipe for all wavelengths into the cassette and the lack of anti-halation backing permits it to pass through multiple layers of film on the spool.
My impression, too, at least with Kodak HIE. Load it in anything other than complete darkness and there's at least a little bit of fogging on the first few winds of the roll. But does Efke IR820 have a polyester base?
No, the IR820 has an acetate base in 35mm. I apparently confused it with the 120 which is polyester.
Are you sure about that? When I recently used IR820 for the first time, I was surprised when I could not tear the film with my fingers, and I had to grope around in the dark for scissors. I assumed the film base must be polyester instead of cellulose because of that.
Hmmm... Well, I'm basing that on what it says on this data sheet which is actually for the Maco IR820 film. My assumption is that the Efke and Maco IR820 films are the same, but maybe that's not true. Is there a data sheet for the Efke IR820? I can't seem to find one.
Here you go... yes, it is the same..http://www.freestylephoto.biz/pdf/MACO_IR820c_AURA.pdf
I load my Leica in the wine cellar just to be safe but I would love not having to do that. More importantly, I am curious as to why the data sheet suggests that the 120 version should also be PROCESSED in the dark.
I load my Leica in the wine cellar just to be safe but I would love not having to do that. More importantly, I am curious as to why the data sheet suggests that the 120 version should also be PROCESSED in the dark.
Yeah, that is weird. I guess I assumed they meant that you can't use a safelight, but that would also apply to 35mm film. I kinda glossed over that thinking, "Well, it's probably pretty dark inside my developing tank." They do say in the data sheet that they have not substantiated reports of plastic tanks or cameras that are transparent to IR. I suspect if Patterson tanks leaked IR, I would have heard about it by now.
I will probably be using a Nikormat to shoot this film. I don't relish trying to load that in the dark. I'm not that adept at loading in in the light.
I load my Leica in the wine cellar just to be safe but I would love not having to do that. More importantly, I am curious as to why the data sheet suggests that the 120 version should also be PROCESSED in the dark.
Are you sure the data sheet says this? I have not read it in some time, but I remember the sheet going out of the way to state that processing in plastic tanks was perfectly safe, and that they had actually tested as much.
The data sheet does say that while 35mm ought to be loaded and stored in total darkness (and that for this very reason, it is better to have it scanned by a carry-on baggage scanner than it is to have it hand checked), 120 can be loaded in subdued light. They state that this is because 35mm light traps are not IR safe. The end seals of medium format film are, however.
I am referring to the Maco data sheet for the emulsion that become Efke IR 820. This is the data sheet that Freestyle links one to if they want to download the sheet from the Freestyle site.
From the sheet:
"It is technically impossible to seal the felt trap of a 35-mm cartridge
against IR radiation. Also, the film base will act as an optical waveguide
for IR radiation. It is because of these facts that MACO IR 820c
and MACO AURA 35-mm films must be taken from the storage container
and loaded into the camera in complete darkness (i.e. in a
changing bag or in a darkroom). Films taken from the container under
light (daylight or artificial) can be expected to be fogged up to about
half the film length (frame 12 to 18)."
and:
"120 roll film should be loaded into the camera or camera
back under subdued light.
Complete darkness is required when loading 35-mm cartridges
into cameras and when loading cut sheet film
backs."
and:
"Plastic Cameras and Development Tanks
"Reports that cameras with bodies made of plastics are not IR-safed
have not been substantiated to date. It could be shown, however,
that the bodies of, e.g., Minox 35 cameras (thin makrolon) and the
Russian panoramic camera Horizon 202 are perfectly suitable for use
with IR film. The same holds for development tanks.
All steel tanks are suitable for developing IR films. The same could
be shown for the development tanks of JOBO, which are made of
makrolon. Problems with other brands are not anticipated. Should
you fear that your tank is not IR-safe, it is recommended [1] that you
wrap it in aluminum foil."
and:
"X-ray Baggage Check at Airports
"X-ray machines at airports, when labelled »filmsafe«, could be shown
not to have any detrimental effect on films, even in case of multiple
exposures (up to 5 times). Fogging during manual checking is much
more likely, though, as the film is taken out of the canister and
exposed to light (see Clause 5). Problems must also be expected
when films are transported in checked baggage. The intensity used
to x-ray this piece of luggage will be increased automatically if it contains
any object that is not easily penetrated by low-intensity x-rays
(such as a.c. adaptors of electronic devices). The higher dose used
in this case may not be film-safe any more. It is therefore recommended
to transport films in your cabin luggage."
Hi 2F/2F..yes, actually on page 7 of the data sheet it is boxed and bold
"120 roll film and sheet film must be processed in complete darkness". Can't figure out why really, since it is kind of contradictory with other statements in the sheet.
In terms of using LEDs, etc, keep in mind that the film is much less sensitive to IR than it is to visible wavelengths, otherwise the filter factor with an R72 would not be 7 stops. The quantity of IR from an incandescent bulb is more than from a green LED but so much less than from the sun that it's irrelevant.
I have loaded/unloaded Efke IR 35mm film in subdued light with, at worst, just a little bit of fogging on the first frame but sometimes no fogging at all.
Efke 120 film is even safer in my experience, once the film is wound tightly then its fine, even in sun light.
I think Efke are just covering themselves as someone mentioned already.
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