Re: Trick for increasing speed of photo papers?

" 4. Hypersensitzation"

Though applied to special emulsions, TEA (triethanolamine) might be worth a
try. You would have to bath the paper in say 2 - 5% TEA prior to exposure.
For Lippmann emulsions this results in a speed increase of 2 - 3 stops.

Martin

----- Original Message -----
From: "Bill William" <iodideshi@yahoo.co.jp>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Thursday, November 18, 2004 10:21 AM
Subject: Re: Trick for increasing speed of photo papers?

> ---
> From: Liam Lawless
> > I haven't tested "speed increasing" ideas, but...
>
> > I'm afraid to tell you but this is not going to
> > work... Pretty much all practical developing agents
> give pretty comparable speed when used at the optimal
> condition...
> ----
> Don't be discouraged by Ryuji's comments. You should try
> it for yourself. You never know what you will discover.
> The developer you are using may not be optimized, and you
> may not notice or care if the there are other changes in
> the emulsion.
>
> There certanily are ways emulsions can be speeded up... it
> is done all the time.
>
> While it is true that a good emulsion is already at or
> near it's best speed, and trying to get more out if it may
> be more trouble than it is worth, it can be done.
>
> I don't know the material you are using but some areas for
> you to consider are:
>
> 1. Washing prior to exposure
> 2. Color sensitization
> 3. Increasing the pH of the emulsion or the developer or
> both...
> 4. Hypersensitzation
> 5. Gold Latensification
> 6. ???
>
> As everyone knows, emulsions increase in speed up to a
> certain peak then the speed starts to fall... at that
> point, they begin to fog more or less rapidly...
>
> You may be able to get some speed just by waiting, or by
> accellerated aging of your material...
>
> I guess you don't have the time or will to go that route,
> but the point is yes it can be done...
>
> But 2 or 3 stops?
>
> That is quite a bit!
>
> But even so, it is a possibility, as new sensitization
> technology has been developed
> which does this exact thing.
>
> Some of the things that can be done may not necessarily be
> speed increasing per se, but for all pratical uses may be
> similiar in that they allow you to get the picture made.
>
> There are many possible roads to travel.
>
> You may not find the Stairway to Heaven, but I hope you
> have a nice trip!
>
> Ray
>
> (Everything said, adding another Ray of Light might be the
> simplest... but Panalure does have a very high speed
> emulsion, and there are others too in the same speed
> range.)
>
> --------------------------------------------
> "Stairway to Heaven - the greatest song ever written"
> Timothy Leary
>
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Received on Thu Nov 18 05:33:53 2004