Re: Maco IR film base compared to Kodak HIE and Antihalation layers

[Eckhard Stephan <eckhard.stephan@xxxxxxxxxxx>]

> 2) Under normal light HIE has a bright green color and Maco 820 IR has a
> dark blue color due to it's antihalation layer.  I then looked at Maco 820
> and Kodak HIE unexposed film through my IR camcorder (with 88A filter over
> the lens). Surprisingly both of them look the same, a very light gray tone.
> Both of these bases allow IR light to pass freely through them.  It is my
> conclusion that Maco IR film's anti-halation coating is only effective for
> deep red wavelengths of light, not near IR light.
> 
> Furthermore, I think the reason Kodak doesn't have an antihalation coating,
> is that it wouldn't be effective in blocking IR light! Afterall these
> antihalation coatings are just dyes, and many people have noted that the
> dyes used in darkly colored clothes don't block IR light at all; instead of
> showing up dark in IR photographs many clothes are light colored/toned. Is
> there a dark colored dye out there that blocks IR light? Probably. Is there
> one that can economically be used in an antihalation layer? Maybe not?
> 
> Peace Rolland Elliott
> ______________________________________________________

Interesting... ;-) Maybe this is the reason why there are halos on
Konica IR, too, although the film definitely has an anti-halation layer.
Your observations make me wait even more impatient for this year's IR
season to begin (about 6 weeks from now on where I live...). Maybe it is
possible to get some nice halations on MACO IR 820, too (still got some
rolls of the prototype in the freezer)... ;-)) ?

Cheers,

eckhard

-- 
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*          Eckhard Stephan             * 
*          Freiburg (Germany)          *
*     eckhard.stephan@xxxxxxxxxxx      *	
*   http://www.eckhards-photobox.de    *   
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