Re: Problem with Wisner 4x5 camera probably solved!

[Jud Hofmann <hofmann@xxxxxxxxxxxxxxxxxxxxxx>]

At 10:51 PM 2/26/97 GMT, George L Smyth wrote:
>Jud Hofmann wrote:
>>
>> One mechanism that could do this fogging is flourescence:  
 
[snip]

>If this is the case, then wouldn't all film be fogged in the same
>manner.  I would guess that the holder would then become useless for any
>film.  

I am in no way a materials technologist, but it seems to me that the
material could flouresce in the infrared only. 

>I am assuming that the makers of film holders chose their
>materials a bit more reasonably.

If it emitted only in the infrared, they never would have detected it at
that time.  It wouldn't be reasonable to test for it since IR film wasn't
around then.  Just another way Mother Nature has of biting engineers &
designers in the tail.

Jud


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