Re: update on lumen prints

Chris,
Quite offten colloidal solution of metal particles will have a different
color in reflected and transmitted light. This is perhaps most striking if
you ever saw a solution of colloidal gold particles. It might be the same
with silver here.
Marek, Houston

>From: SteveS <sgshiya@redshift.com>
>Reply-To: alt-photo-process-l@sask.usask.ca
>To: alt-photo-process-l@sask.usask.ca
>Subject: Re: update on lumen prints
>Date: Fri, 18 Nov 2005 11:39:17 -0800
>
>You mentioned below a single weight paper. What brand was the single
>weight?
>
>S. Shapiro
>----- Original Message ----- From: "Christina Z. Anderson"
><zphoto@montana.net>
>To: "Alt List" <alt-photo-process-l@sask.usask.ca>
>Sent: Friday, November 18, 2005 6:36 AM
>Subject: update on lumen prints
>
>
>>Just a quickie,
>>It's getting to be about the end of the semester and the student doing
>>lumen prints is wrapping up her project. Thanks to Don Bryant's offlist
>>generosity (DON what do i owe you for shipping?????) the favorite paper
>>she says is a single weight Portriga grade 6. I think she means Brovira
>>but will have to check with her again to make sure it is that, as Don gave
>>us a stack of all kinds of paper, both being in there. Don, you made this
>>student's "day" and we both thank you.
>>
>>Oh, another paper that is beautiful is Forte. Of course. Forte and
>>Bergger are my faves anyway. Those were not outdated. The RC Forte
>>polywarmtone is dramatically pink.
>>
>>The interesting thing I want to report is that there is a remarkable
>>difference when these single weight papers are held to transmitted light.
>>It does not happen in the double weights. The dull olive green on the
>>surface of the paper shows as brilliant violet when held up to light. I
>>am going to hazard a guess that it is the Mie effect (written about in
>>Scientific American a couple decades ago) and that the different sizes of
>>granules and types of granules of silver react differently to overexposure
>>of the sun and refract color differently, but somehow the ones that
>>refract violet are behind the olive ones. I can't think of another reason
>>why the purple shows only with transmitted light so maybe someone else can
>>make a better guess than that. Whatever the reason, she has decided to
>>display a few of them in lightbox type frames. Gorgeous possibilities.
>>bye
>>chris
>>
>>
>>
>
>
Received on Fri Nov 18 14:58:32 2005