Re: Dry Plate Speed & Shelflife

> What kind of speed and contrast can one get with that procedure?

I don't know about speed/contrast (in photographic terms). Principally, I
believe, you might design any kind of SH emulsion on such grounds.

> Since there is no ripening or digestion step except reduction
> sensitization by ascorbate, I suspect the speed would be exceedingly
> low.

No, I don't think so. Speed levels of the emulsions produced according to
the "Diffusion method" are better than some of the commercial (holographic)
emulsions. Besides the ascorbate sensitization, one of its advantages stems
from the high amount of silver halide present in the emulsion. Regarding
ripening (and possibly gold sensitization), I guess this could be easily
integrated into the schedule of this method.
As you know, it's always much easier to inrease grain size than to
achieve the opposite.

> That is to be expected for holography where the application
> demands extremely high resolution.

Well, you might be surprised to learn that the power levels involved with
those lasers - most of the time - are extremely low. Whereas youre likely to
handle several kilowatts of light power, we're usually dealing with a few
milliwatts only.

> But better emulsion for still
> photography can be made with a conventional way.

I guess it depends on the scale of emulsions to be produced. For small
experimental batches the bathing methods might remain attractive: no need
for double-jets - though I have to admit reproducibility might be an issue.

Anyway, you might at least give the ascorbate reduction sensitization a
try...

Martin

----- Original Message -----
From: "Ryuji Suzuki" <rs@AgX.st>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Wednesday, March 02, 2005 6:43 PM
Subject: Re: Dry Plate Speed & Shelflife

> From: MARTINM <martinm@SoftHome.net>
> Subject: Re: Dry Plate Speed & Shelflife
> Date: Wed, 02 Mar 2005 11:32:36 +0100
>
> > http://cabd0.tripod.com/holograms/id3.html might be easily adapted
> > to purely photographic applications. Since it involves ascorbate
> > reduction sensitization as well the possibility of TEA
> > (triethanolamine) hypersensitization, reasonable speed might be
> > expected.
>
> What kind of speed and contrast can one get with that procedure?
> Since there is no ripening or digestion step except reduction
> sensitization by ascorbate, I suspect the speed would be exceedingly
> low. That is to be expected for holography where the application
> demands extremely high resolution. But better emulsion for still
> photography can be made with a conventional way.
>
> I sent the most stripped down emulsion formula in my notebook to a
> limited circulation among several people some time ago, and as far as
> I know, one tried and had good result, although his setup wasn't
> anywhere near ideal.
>
> --
> Ryuji Suzuki
> "Well, believing is all right, just don't let the wrong people know
> what it's all about." (Bob Dylan, Need a Woman, 1982)
Received on Thu Mar 3 02:08:14 2005