Re: Tonal inversion (was (Gum) Tonal scale)

Glad you liked them, Chris :-)

Thanks for the info, I will be checking what was said in 2004 about
the tonal inversion. I have never seen it happen with digital negs,
but anyway, I still take some large format negative from time to time.

And then, at a time when I was working with x-ray film, this 'effect'
gave me such headaches! I would really like to know what is happening.

Tom

At 17:13 03/12/2005, you wrote:
>Good morning!
>First of all, Tom, I loved your mask images. Both are equally
>effective but i do prefer the golder one because the gold really
>looks like gold!
>
>Second of all, the reverse tonal palette:
>
>yes, we talked about this on list not last summer but summer
>2004...I was testing the addition of lemon juice to the gum mix to
>see if it lengthened the tonal scale, etc., following a
>recommendation by Demachy.
>
>What I found was this reverse solarization effect that Judy had
>previously described. The more acid added, the stronger it
>became. It was not because I added more fluid and the gum coat was
>more diluted, because I balanced added drops of lemon juice with
>added drops of water.
>
>I figured that Judy and Mike Ware were correct, that staining was
>held back by a partially hardened gum, so that pigment was unable to
>sink into the paper fibers.
>
>I also felt that the acidity factored in--the more acid, the more
>what I might term "mordanting" of the color to the paper
>surface. Whether the acid destroys the paper sizing as Joe has
>suggested or some other attraction factor is at work, I don't know.
>Chris
Received on Sat Dec 3 14:25:45 2005