From: "Walt Wayman" <hiwayman@xxxxxxxxx>
> A look back into history, i.e., my Amphoto Lab Handbook, circa
> 1970, shows a daylight ASA speed of 50 for Kodak High Speed
> Infrared Film
<snip>
> ... "Safelight: Total darkness
> required," there are no admonitions about loading and unloading
> the camera in total darkness.
>
> In fact, on the very next page, which is the data sheet for Kodak
> High Speed Infrared sheet film 4143, which has (or had) an even
> higher daylight ASA of 80 with the same filters, there is this
> notation: "Safelight: Total darkness required. A safelight filter
> Series 7 (green), in a suitable safelight, with a 15-watt bulb can
> be used at 4 feet."
>
> Which leads me to ask: Just how fast is the current infrared film?
>
According to the Kodak website, HIE/HSI (HSI is now discontinued, as is
sheet HIE) has the same "speed" as in days of old: roughly 50 ASA.
The real problem/benefit with HSI/HIE is the lack of an anti-halation layer.
As Josh Putnam has posted previously, this allows white light to bounce all
of the way through a roll even when just the leader is exposed. AFIK, Konia
IR 750 and the Macophot "twins" (750 and 820) DO have anti-halation layers,
making them easier to handle.
The benefit to using HIE is the "glow" that comes in using a film that
halates (gets a "halo" around the highlights). People love the HIE "glow"
and put up with the temperamental handling characteristics. Reflected light
from within the camera is a problem with HIE, our dimpled OM pressure plates
will sometimes show up on the negative.
Jamie
Fort Myers, FL
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