From: Clay Harmon (wcharmon@wt.net)
Date: 09/29/02-06:53:31 PM Z
Sandy wrote:
>
> I have some doubts that the self masking effect of platinum is strong
> enough to have any significant impact on the shadows.
I'm glad you mentioned the alleged self-masking of DOP platinum.
Platinum/palladium self-masking has assumed almost the status of dogma.
I hear it repeated regularly. Has anyone out there ever tested this? I
have done some limited tests with the ubiquitous step wedges, and
frankly, I think it may be baloney. If the process were truly self
masking, then the contrast of the resulting print should decrease with
increasing amounts of exposure. In fact, the slope of the curve stays
the same for a given sensitizer mix and only moves to the right when
you plot the typical H and D curve. In fact the main thing you notice
with super-maximum exposures is some slight solarization or bronzing in
the darkest values. Anyone out there tested this with any minor amount
of rigor?
I'd be interested to see some information on this if it exists.
Clay
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