[pure-silver] Re: Grain Size

Hi Bogdan,

One could do that, but the reason that people usually use D-76 diluted is for 
the type of negative it then produces.  The maximum action of sulfite is around 
7.5% and not the 10% that is used in such developers as D-76 and D-23.  So you 
would have to calculate the actual concentration for the added sulfite solution 
based on the dilution that you intend to use.  The actual increase in 
graininess is not that much.  You are not going to see boulder size grains 
using diluted D-76.  In any case Xtol is a better choice for finer grain than 
D-76.

Jerry

-----Original Message-----
From: pure-silver-bounce@xxxxxxxxxxxxx 
[mailto:pure-silver-bounce@xxxxxxxxxxxxx] On Behalf Of Bogdan Karasek
Sent: Thursday, October 26, 2006 5:44 PM
To: pure-silver@xxxxxxxxxxxxx
Subject: [pure-silver] Re: Grain Size


Hello,

In order to compensate for the increased graininess due to dilution 
(1:1) when using D-76 and thus a lowering of the sodium sulfite, would 
it be appropriate to add sodium sulfite if one is using D-76 at 1:1 
dilution?

If so, then in what quantities?

regards,
Bogdan

Richard Knoppow wrote:
> 
> ----- Original Message ----- From: "Ralph W. Lambrecht"
> <info@xxxxxxxxxxxxxxxx>
> To: "PureSilverNew" <pure-silver@xxxxxxxxxxxxx>
> Sent: Wednesday, October 25, 2006 6:26 PM
> Subject: [pure-silver] Grain Size
> 
> 
>> I'm confused by a discussion in a German forum and also by some text 
>> in Ansell/Troup.
>>
>> Does a higher developer dilution (compensated by an extended 
>> developing
>> time) increase or decrease grain or granularity?
>>
>>
>>
>>
>>
>> Regards
>>
>>
>>
>> Ralph W. Lambrecht
>>
>> http://www.darkroomagic.com
>>
> 
>   Older books explain the difference in developers when diluted as 
> being
> due to salt effect, the solvent effect of Sulfite, and pH. According to 
> Ryuji Suzuki, these explanations may not be completely valid. In 
> particular, the effect of "grain clumping" due to emulsion softening may 
> not be significant with modern, highly hardened, emulsions.
>   The effect of dilution seems to depend on the formulation of the 
> developer. High sulfite developers, for instance, D-76, D-23, D-25, and 
> others, become _more_ grainy as they are diluted. Some relatively low 
> sulfite developers of relativelly high pH, such as Rodinal, become 
> _less_ grainy as they are diluted. The old books attribute the grain of 
> Rodinal and similar developers partly to grain clumping but it must also 
> be due to the activity of the developer and the shape of the crystals 
> developed from the halide. The sulfite in high sulfite developers tends 
> to produce filementary crystals. Under the electron microscope these 
> tend to look like little bunches of steel wool. More active developers 
> tend to develop silver crystals that are shaped like the halide crystals 
> they come from. Since the actual silver crystals are microscopic visible 
> and printable grain are actually due to the combination of many crystals 
> in the emulsion. The shape of the individual crystals evidently affects 
> the way they combine statistically to produce both image and grain.
>   So, the answer to your question is _both_. Developers like D-76 become 
> _more_ grainy when diluted, Developers like Rodinal become _less_ 
> grainy. There are probably some developers whose graininess is not 
> affected by dilution.
> 
> ---
> Richard Knoppow
> Los Angeles, CA, USA
> dickburk@xxxxxxxxxxxxx 
> ======================================================================
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> 

-- 
________________________________________________________________
   Bogdan Karasek
   Montréal, Québec            e-mail: bkarasek@xxxxxxxxxxxx
   Canada

                   "I photograph my reality" 
__________________________________________________________________


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