Archived posting to the Leica Users Group, 2002/01/03
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>Brian:
>
>I think if you keep it in the dark, it doesn't matter what colour
>the bottle is. I remember reading years ago that the brown glass
>was to keep some of the light out.
>
>Regards,
>
>Robert
>
>At 07:20 PM 1/2/2002 -0800, Brian Reid wrote:
>>Now I just need to get some of these 250ml bottles. Does anybody
>>have a recommended vendor? Does anybody actually know enough
>>chemistry to know whether a blue bottle will have the same
>>preservative value as a brown bottle? The Kodak web site is silent
>>on this.
>>
>>Brian Reid
>
>
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Brown bottles are better because they only admit light waves of
longer wavelengths, while blue bottles and clear bottles admit light
waves of shorter, more energetic wavelengths, which are more likely
to add enough energy to an electron to dislodge it, breaking down a
developer molecule. It's not a resonance thing, but purely evergy
level dependent. In a room that is used as a darkroom, it doesn't
matter hugely, as there usually isn't a lot of energy from short
wavelength light bouncing around.
- --
* Henning J. Wulff
/|\ Wulff Photography & Design
/###\ mailto:henningw@archiphoto.com
|[ ]| http://www.archiphoto.com
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