Chemical Formulations and Fixer question

[ciaran_mcmenemy]

<p>Hi!<br>

I'm in the mood to experiment when it comes to developing, since b&w and C41 are familiar to me. I tried bleach-skipping (C41), are there any other things to try? <br>

Is b&w reversal bleach different to C41 bleach? I think it would be, since, from what I've read, it <em>removes</em> the developed silver, while C41 bleach <em>reduces</em> the developed silver back to halide.<br>

I'm interested in making chemicals. Does anyone have any 'ingredients'? The obvious one is caffeine and vitamin C, I'm wondering if anyone has any of their own concoctions.<br>

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What does b&w fixer do, exactly? does it stabilise the developed silver and remove the halides? I'm wondering what you would see if you pulled the film out of the tank after the develop/wash step.<br>

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<br /> </p>

[larrydressler]

<p>Alchemy is a dangerous and slippery slope. Bleach for B&W is similar to color but much more caustic. I get my Sulphuric acid in powder or liquid form from auto part stores. Fixer for Color and B&W is pretty close to the same. Stabilizer for Color i has changed through the years and the film with it because of EPA regulations in many countries. </p>

[peterbcarter]

<p>Reversal bleach is a completely different fish than C41 bleach. Reversal bleach removes developed silver and C41 bleach bleaches all the silver. BW Bleach is also HIGHLY acidic and anything lower than PH 6.5 damages the dyes.</p>

<p>The C41 process is a process of standards. Unlike B&W, there really is only one way to develop it. That is how they got consistency with the product completely controlled by the manufacturers. </p>

 

[randrew1]

<p>The fixer was the primary contribution of Louis Daguerre in 1839. It is called a "fixer" because it fixes the image (makes it permanent). If a B&W image is not fixed, the undeveloped silver halide will eventually print out (be reduced to metallic silver) and destroy the image. The fixer works by converting the undeveloped silver halide to silver thiosulfate which is soluble and will wash out of the film. </p>

[martin_dake]

<blockquote>

<p>The fixer was the primary contribution of Louis Daguerre in 1839.</p>

</blockquote>

<p>The fixer that we know today as hypo was the primary contribution of Herschel who then shared his discovery with Daguerre, prior to that Daguerre used hot salt water solution.</p>

[larrydressler]

<p> May I butt in and say. The books and formulas are online and known. The new 55 Polaroid instant monobath was derived from an old member here.</p>

[randrew1]

<p>After checking some sources, I believe Martin is correct about Herschel's discovery of sodium hyposulfite as a solvent for silver halide. Daguerre often gets the credit because he published first. </p>

[ciaran_mcmenemy]

<p>thanks for the responses!<br>

I was wondering if a C41 bleach could be used on bw. That depends on the way it interacts though. If C41 bleach removed all silver wouldn't there be no need for fix? I was thinking it either 1) rehalogenises the developed silver, leaving it to be fixed, or 2) reacts with it and takes it off the film, into the solution. Someone educate me!!<br>

Tetenal C41 uses a combined bleach-fix, but since the chemical concentrates for bleach and fix are separate, could I mix the bleach with water, and the fixer with water, for two solutions? That would be more versatile, at least.<br>

I was wondering what 'print out' meant. thanks Ron. I appreciate the chemical naming too! I tried a frame without fixing it, and it actually looks quite interesting. I will keep watch over it to see how it changes.</p>

[Bill C]

[Ciaran] " I was thinking it either 1) rehalogenises the developed silver, leaving it to be fixed, . . ."

 

Yes, that's basically what happens with C-41 bleach. If you ran b&w film through a C-41 process you'd expect to get blank (or nearly so)

film.

[glen_h]

<p>Seems to be described here:</p>

<p>http://www.oocities.org/sunsetstrip/studio/4474/negtoposdeveloper.html</p>

<p>mostly for movie film, but the chemistry should be pretty much the same.</p>