Green D76

[steve_beswick]

I used a small batch of D76 today to develop 1 roll of Delta 400 and then 1 roll of Arista EDU 100. Both were 120 format. When I was

done with the Arista the developer had turned a light Palmolive green. Is this normal? What does it mean?

[thomas_taylor2]

<p>H1N1</p>

[bobcossar]

<p>Yep......it's just the backing dye used on the Arista....No worry at all...</p>

[steve_beswick]

I'm of the "mix it back in with the gallon, dump the gallon as a whole" mindset. If I put the green stuff back in with the

regular, will it hurt anything?

[bobcossar]

<p>No....that will cause no problems at all.....Its quite surprising how many backing dyes are actually in use......almost all of the ones you really notice are on roll film, and particularly so in the 220 size.....Regards...Robert</p>

[steve_beswick]

<p>Thanks for the quick responses everybody!</p>

[evan_goulet]

<p><em>"I'm of the "mix it back in with the gallon, dump the gallon as a whole" mindset. If I put the green stuff back in with the regular, will it hurt anything?"</em></p>

<p>Does this statement above mean that you are not using the D-76 as a "one shot" developer? <br>

Most of the home developers will recommend discarding the small volumes of developer used to develop one roll.</p>

[bobcossar]

<p>I do agree with Evan on his point.....one-shot usage is much better for consistent results. I only answered as I did with reference to the "polluting" aspect of the dye...Regards, Robert</p>

[frank.schifano]

<p>Yes, it is quite normal for that film and no it won't hurt anything. The same film in 135 format doesn't do this. If you are having problems with your developer, this is not the cause of it.</p>

[Vlad Soare]

<p>It's normal and won't hurt anything, but if it bothers you, then next time you can try prewashing the film. The green dye will come out in the prewash, and the developer will stay clean.</p>

[Filmnoob]

Im so glad I found this old thread! I just developed some arista edu 400 in 120 today for the first time using d76. I was quite surprised to see the developer had turned a bright almost neon green color. I’m glad to read it’s of no concern! 

[glen_h]

TMax films have a nice pinkish or purplish dye, which makes developers pink at very low concentration.

(And films pink if you don't fix long enough.)

 

Before I developed my first roll (55 years ago) I had a practice roll to load.

I am not sure now where it came from, but I do remember that it was pink.

 

[rodeo_joe1]

2 hours ago, glen_h said:

(And films pink if you don't fix long enough.)

Fixer doesn't remove the pink tint Glen, no matter how long you fix (within reason) or how fresh the fixer is. IME it's only removed or greatly reduced by an extended final wash. Even then it doesn't always completely go, but it's harmless and will eventually fade through oxidation(?) or exposure to light. Often during just the short time the film is hung to dry. 

In any case, the developer comes out of the tank decidedly pink after processing T-max. 

[Alan Marcus]

The photographic image can be ruined by a phenomenon called halation. Specular highlights (bright refection from metal or glass or polished surfaces) play on the film’s surface during exposure. These super bright light rays will penetrate all the way through the light sensitive emulsion, hit the back pressure plate of the camera where they will be reflected into the film from the rear. The result is a halo like ring of exposure spreading out from the highlights. Well studied by Professor Hermann Vogel, Berlin Technical, who in 1873 added dye to film to absorb this unwanted light. The color of the dye is the color the film is least sensitive too.

This addition is called an antihalation coat. Vogel tried many ways to remedy. Once he dyed the entire emulsion yellow. This worked but to his surprise, the emulsion formula gained sensitivity to green light. Heretofore it only responded to blue light. His improved emulsion yielded black & white emulsions that imaged with greater accuracy. His improved emulsions were called orthochromatic. His graduate students made further gains by adding different mixes of what is called sensitizing dyes. This resulted in panchromatic films, sensitive to blue, green, and red light.

The developer solution which is mainly water, is a solvent for the annihilation and the sensitizing dyes. Thus, the fluid changes colors as films are being developed. These color changes are harmless.

Note: The developing agents used in modern film developers are related to benzene. Benzene was initially obtained from coal tar. The various developing agents have an affinity for oxygen. Thus, they take on oxygen that is dissolved in the waters of the developer. The oxidized developing agents revert to coal tar. Working developers are usually straw colored, they change to black and become opaque as they work and age. Developers contain a preservative that retards aerial oxidation and neutralizes its staining ability. 

[glen_h]

On 10/29/2022 at 1:50 AM, rodeo_joe1 said:

Fixer doesn't remove the pink tint Glen, no matter how long you fix (within reason) or how fresh the fixer is. IME it's only removed or greatly reduced by an extended final wash. Even then it doesn't always completely go, but it's harmless and will eventually fade through oxidation(?) or exposure to light. Often during just the short time the film is hung to dry. 

In any case, the developer comes out of the tank decidedly pink after processing T-max. 

 

Diffusion problems are exponential, so yes it never gets all the way out.

 

Well, also, T-Max films are T-grain, and the grains dissolve from the edge.  It takes longer to fix them.

Also, it is AgI along with the AgBr that makes them T-grain.  AgI crystallizes hexagonal, and AgBr cubic.

As you change the ratio, there is a transition.  I believe also that AgI fixes slower.

 

In any case, the actual instructions mention fixing time and pink tint.