D-76, Solvent Developer?

[rover]

As you may know, you are living a film processing mid life crisis with me.

So, this is what I just read, a document by H. Lynn Jones from Austin, TX. It is available on the internet, but copyrighted so I will only share a snippid.

He identifies D-76 as a silver solvent developer, but later adds:

"D-76 diluted 1:1 is a very popular incarnation of the developer. When diluted the sulfite level falls to 50 grams per liter. Since 80gpl is required for silver solvency, it no longer functions as such and in fact is now a high resolution, compensating, "one shot" developer similar in many ways to Rodinal and TEC."

That makes sense to me, now I have some direction in testing D-76 and may have a little more understanding of what and why my results are what they are.

 

[kmack]

OK, you need to get this out of your system. Don't fiddle around at the edges...
Take the plunge and become a kitchen sink chemist. Get your self a copy of The Darkroom Cookbook and do the mad scientist thing for a while.

You know you really want to start mixing up your own PC-TEA or Harvey's 777.😀

 

[willie_901]

If stock D-76 dissolves all the silver, it seems D-76 1:1 has enought sulfite to dissolve 5/8 of the silver.

Unless silver is completely insoluble until the sulfite concetration reaches 80 gpl (unlikely), I think D-76 1:1 could act more like solvent-developer than not.

On the otherhand, I have not practiced inorganic chemistry for decades.

The temperature and water mineral content used to dilute the D-76 could effect the silver solubitity as well.

Just a thought,

willie

 

[rover]

If stock D-76 dissolves all the silver, it seems D-76 1:1 has enought sulfite to dissolve 5/8 of the silver.

Unless silver is completely insoluble until the sulfite concetration reaches 80 gpl (unlikely), I think D-76 1:1 could act more like solvent-developer than not.

On the otherhand, I have not practiced inorganic chemistry for decades.

The temperature and water mineral content used to dilute the D-76 could effect the silver solubitity as well.

Just a thought,

willie

Stop trying to confuse me. 😎

kmack, no I have the "Cookbook" but no desire to be a chef.

In a real mid life crisis a guy could be expected to go out and buy a sports car. In mine I may go out and buy an enlarger.

Better?😕
:angel:

 

[Stephanie Brim]

rover, if you want to get rid of said "cookbook", I'm wanting to become a "chef".

 

[markinlondon]

There's a nice history of D76 here. Ilford ID-11 is the "classical" formula. Kodak's D76 has been modified (new and improved?) to allow packaging as a single powder. In My way with the miniature (1941), Lancelot Vining identifies fine grain as one of the key ingredients of a successful miniature (i.e. 35mm) negative and recommends D76 for the purpose. I don't think anyone was diluting it in those days.

 

[ronnie_retro]

Great reference article!

Great reference article!

Thanks mark for a very informative link. All you ever wanted to know about D-76.
I find it interesting that this developer has such a simple chemical composition but is still hard to beat today, 75 years later.
The section on photographic sound recording I think is of particular interest since the critical nature of the exposure/development process was really explored thoroughly as a result.

Others looking for a good photographic technical reference may wish to pick up a copy of one of Paul Boucher's "Fundamentals of Photography" editions. Abebooks
(www.abebooks.com) sells editions starting at $1.10 - the price is right!

 

[Ronald M]

Tried a lot of thing over 50 years and came to settle on D76.

I mix my own from bulk chemicals and get the same results as package mix.

Just don`t leave it in a partially full bottle as it will get active and then die fast.

Noticable change occures in a week. I use small one shot glass bottles.

 

[markinlondon]

D76/ID-11 (my, I get sick of typing that) is not only hard to beat for sheer quality of results with my favourite films (HP5, Tri-x, FP4, Delta 100) but is amazingly versatile. I use it as stock and reuse with time adjustments, usually getting 12 rolls out of it before not trusting it further (DISCLAIMER: test to see if this is for you - DON'T take my word for it). This is very economical. Used 1:1 it's still pretty good value (in larger packagings) with very little degradation in performance. Used at 1:3 it's on the way to an acutance developer. And they invented this in 1926! Actually, I think it's the other way round, ID-11 is so good they tune the films to the developer.

Thanks for the book tip, Ronnie. I love old photography manuals as the Lancelot Vining reference probably shows.

 

[kaiyen]

Using it as stock multiple times without replenishment isn't terrible, as long as you have the number of rolls that you run through dialed in. It's against conventional wisdom _only_ because it's not recommended for folks getting started. I re-use Microphen stock all the time, for instance, but I have tested it and know that it'll work at about 10 rolls per liter.

First off, to clarify an earlier point, D76 full strength doesn't disslve all the silver. That's like pouring fixer in first 🙂. Solvent developers just dissolve the edges of the silver grains, so that you get finer looking grain via decreased micro contrast (the contrast from edge to edge of silver), but at the cost of decreased sharpness.

Indeed, as you dilute you are decreasing the amount of sulfite in the total solution, thereby decreasing the solvent effect. However, in the spectrum from 1+0 to 1+3 (the common and advisable dilutions), 1+1 is, not surprisingly, kind of in the middle. In my opinion, I'd still call it a solvent developer since its acutance is not as high as, say, Rodinal, which is kind of my "beginning" point for acutance developers (Rodinal isn't _that_ high in terms of sharpness either, by the way. There are some _really_ high definition developers out there).

So some consider 1+1 an acutance developer, and some don't. I don't, and neither do Anchell or Troop, at least according to the FDC. Bottom line - people use it because it's a good middle ground for starting out. It's a good compromise between solvency and acutance.

Of course, a developer like D76 is also great for learning about developers. Mix it one way, and you have a relatively fine grain developer without a massive speed loss (as compared to, say, microdol-x). Mix it another, and you have a relatively high-defintion developer with terrific economy. Or, mix it in between and get a good baseline combination.

allan

 

[markinlondon]

Using it as stock multiple times without replenishment isn't terrible, as long as you have the number of rolls that you run through dialed in. It's against conventional wisdom _only_ because it's not recommended for folks getting started. I re-use Microphen stock all the time, for instance, but I have tested it and know that it'll work at about 10 rolls per liter.

(big snip)

allan

Absolutely, Allan. I have tested for capacity and get 12 rolls from a litre pack of ID-11 made with boiled and filtered water and stored in a 1l Pet drinks bottle (green or brown) squeezed to exclude air. I have not gone beyond 12 rolls as this is pushing Ilford's stated capacity. As for time adjustments, I find 10% extra time per two rolls is adequate and not the 10% extra per roll that Ilford suggest. the last roll is barely distinguishable from the first.

 

[kaiyen]

Mark,
Great example of how to do it the right way. For anyone getting started that reads this, it's good to have such a technique qualified appropriately.

allan