"piterengel" <pslaviero@[EMAIL PROTECTED]
> wrote in message
news:1193310410.543853.306920@[EMAIL PROTECTED]
> On 25 Ott, 01:50, dan.c.qu...@[EMAIL PROTECTED]
wrote:
>> > "Richard Knoppow" wrote:
>>
>> > ... but lith film remains because it is used
>> > in a number of alternative photographic processes
>> > and for special effects such as masking.
>> > Richard Knoppow Los Angeles, CA, USA
>>
>> Check your local printing supply outlets or visit via
>> the WWW
>> Valley Litho, a Mid West mail order supplier of a vast
>> selection
>> of press room supplies including a large selection of
>> lith - half
>> tone process films and developers.
>> Should add, also a somewhat unique assortment of film,
>> paper, and darkroom supplies. Dan
>
> Well, after all these answers I want to try to use ID-13
> and Kodak
> D-85, for 2-3 mins with fils.
> I have a matter with sodium bisulphite, ttah appears in
> D-85 formula.
> I've not this substance available, can I replace it with
> somenthing
> else? Is it really necessary?
> Thanks, I'll let you know the results of my tests.
> P.
>
Photographic sodium bisulfite is actually mostly sodium
metabisulfite and metabisulfite can be substituted.
Sodium sulfite is not the same as the bisulfite. Sulfite
is slightly alkaline, bisulfite is slightly acid. The two
make a buffer and are used together, for instance, in Kodak
fine grain developer D-25 and in Kodak Hypo Clearing Agent
to get a neutral pH. Kodak has two versions of D-85, a
single solution developer, D-85 and a two solution version
called D-85b. The two solution version has better keeping
properties. Both formulas specify potassium metabisulfite. I
think the sodium form will work as well. Use whatever you
can obtain most easily. Agfa/Ansco had similar formulas
which call for sodium bisulfite so evidently the cation does
not matter. The bisulfite of the Ansco formulas is, like
Kodak, actually metabisulfite.
--
---
Richard Knoppow
Los Angeles, CA, USA
dickburk@[EMAIL PROTECTED]
|
