[alt-photo] Re: Nature of Curtis Orotones WAS Re: wet-plate collodion

[Jeremy Moore]

You are correct, Etienne--and you can't be overly technical where I'm
concerned, I just love this stuff!

Would you agree with a short-hand definition of an Ambrotype as a
"positive-appearing wet plate collodion negative on glass"?

-Jeremy-

On Wed, Apr 14, 2010 at 7:36 PM, etienne garbaux
<photographeur at nerdshack.com> wrote:
> Jeremy wrote:
>
>> I have never heard of them being
>> Ambrotypes (positive wet plate collodion on glass).
>
> To be technical (perhaps overly so), ambrotypes aren't really "positive wet
> plate collodion" images, at least as that term is normally used.  Viewed by
> transmitted light, they are more or less normal-looking negatives, with more
> silver in the highlight areas and less in the shadow areas.  They appear
> positive for the same reason a daguerrotype and a tintype do -- because one
> develolps the silver to look whitish or grey rather than black, and then
> looks at them by reflected light with something dark behind them (in the
> case of daguerrotypes, the dark is actually in front (typically, the velvet
> lining of the case), and you are viewing it in the mirror of the polished
> plate where no (or little) image silver was deposited.  So they look lighter
> where there is more silver and darker where there is less.  You can get the
> same effect (to a lesser degree) with an ordinary B/W negative if you hold
> it with something dark behind it and catch the relected light just right.
>
> Brest regards,
>
> etienne
>
>
>
>
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