Dumb Question here (D-76 replenisher)

[filmtwit]

but I've not had much luck finding a full answer. So . . .

I picked up a bunch of used darkroom equipment and in and among the stuff was a can of Kodak D-76 replenisher. I've never used the stuff and from what I've read you add it used D-76 mix. At what point should it be used? Or better yet, how do you use it?

Thanks,

[JohnTF]

I used it a very long time ago.

Stock D76 was used to develop film, and according to the amount of film, a small amount of the replenisher was added to maintain the working chemistry of the stock solution.

It was not long until I simply bought gallon size mixes for D76, diluted it 1:1 for use, and discarded the soup after one use. Simpler, with less margin for error and/or contamination.

Personally, I prefer Xtol.

OTOH, D76 and D76 replenish-er 's formulas are published, so you can look them up, and you can always mix it from scratch, not too difficult if you have a decent scale and the component chemistry.

Regards, John

[Tom A]

It is a slightly different formula from the D76 and you add it to your "stock" D76 after you processed the film. The general rule of thumb is to add 20 ml of replenisher for every roll of 35 mm you process.
Easiest way is to pour your D76 (stock solution - not 1:1) in your developing tank and then add the replenisher in the beaker (I usually do 5 roll runs, so I add 100 ml to the beaker) and pour the D76 back after the run and decant the excess so that when you put it back in the bottle it is filled to the brim. This reduces the risk for oxidizing. I usually dump the D76 once I used up all the replenisher in it. D76 will "age" and can give you a bit rough and grainy negatives once it is getting old.

[filmtwit]

Most of work is 1+1 solution.
So it sounds like using replenish-er after the fact might not work that well?

[Tom A]

I have never tried it with 1:1 dilution. Might work but a bit risky. I always use 1:1 dilutions as a one-shot developer - only replenish when using a stock solution.

[Vincent.G]

Dear Tom

Is it safe to say developing should be halved when just using the stock solution?

Should the D-76 be used as a push developer? I tried with Tri-X rated at 1600 and developed it in 1+1 dilution for 13min and the negatives turned out very grainy.

[filmtwit]

Thanks folks. I guess once I have enough used once 1+1 solution I'll add the replenisher and see what results I get!

[Teuthida]

Originally Posted by Vincent.G

Dear Tom

Is it safe to say developing should be halved when just using the stock solution?

Should the D-76 be used as a push developer? I tried with Tri-X rated at 1600 and developed it in 1+1 dilution for 13min and the negatives turned out very grainy.

Forgive me for answering a q for Tom, but halving development time from 1:1 dilution isnt necessarily correct. Check the digitaltruth website for specific times as full dilution.

As foe D76 as a push developer, my experience is that it works well with TX pushed to 800 or 1600. The increased grain is not particular to D76. All pushed film will exhibit increased grain regardless of the developer used.

[sevo]

Replenishers replace the amount of water and chemistry used up in the processing. Compared to stock that means they contain more of the active developer chemicals (which are not only carried over into the next step, but also used up and oxidized), while they contain slightly less of the passive components (alkalines, bromides, sulphates etc.) as evaporation would otherwise increase their concentration over time.

The difference will be quite irrelevant at the current scale of black and white processing (where the developer going stale over several days of disuse is a far more common occurrence than over-use), hence b&w replenishers are pretty much a historical reference by now. But back in the heydays of colour film, large labs going though thousands worth of chemistry a day even employed their own staff chemist to permanently fine tune the replenisher composition.

[JohnTF]

RA 4 seemed so "bullet proof", that simply topping up the slot with new solution kept it pretty well replenished. I used the Jobo slot processor.

Regards, John

[clayne]

I'm surprised no one has touched on the beneficial aspects of developer seasoning yet. It's not only just to save on chemicals.

[Nokton48]

Diluted one-shot developers are NEVER replenished. They are simply poured down the drain after use. I add 20ml of replenisher per 36exp roll (to the stock solution), and the results are consistent and good.

"Seasoning" is adding replenisher over a long period, which "sweetens" the soup. I like using seasoned developers.

[KenR]

I tried replenishing D-76 for one set of negs and never used it again. The times were too short in straight D76 so that I got uneven development. Diluted 1:1 gives somewhat longer times and eliminated the problem. Most people consider D76 1:1 the "standard" against which all other developers are judged - a compromise in terms of speed, grain and resolution that most people find quite pleasing.