Why not 2 baths developer only?

[john_s]

I think you'll find that it's not that at all if you test it. The ratio of the agents is different, the amount of sulfite is different, and the buffer setup is different. So, no, not just divided D-76. Having used quite a lot of divided D-76 (both Haist and Vestal varieties), I can also attest that it works quite differently. Being speed-neutral or speed-boosting (2B-1) vs speed-losing (divided D-76) not being the only major difference. Paul changed the amount and ratio of the developing agents which moves it closer to the ratio that a theoretical D-76 would have if we were to accept that some amount of phenidone substituted for some amount of metol would produce identical results if the superadditive relationship remained the same. That does not make it divided D-76.

I think Lachlan considers many developers to be D76 derivatives. In a post last year he states that Pyrocat is a D76 derivative too.

ID-11 alternative?

That's an awesome resource, thank you! I'll be able to get to it when you provide the recipe to combat laziness 🙃 No, seriously, it does make it seem doable to my non-chemist brain. If you can make a cake, you can also scratch-mix a developer. Actually, it's even simpler and more fool proof...

www.photrio.com

 

[Sidd]

! PC-512 looks interesting. I'm going to read that thread. I'm sure I'll have a question about it soon.

Definitely try PC-512, it's a wonderful developer. Presently I am mostly using it as my go to developer.

 

[Lachlan Young]

many developers to be D76 derivatives.

It's about the developing agent relationships. The buffering and target pH were being played around with by Kodak etc from day 1.

PQ offers some potential inherent benefits for film development that MQ doesn't. Most of the purported effects of the staining developers come from the effects of either high dilution metol-only developers or the effects of a PQ type (Catechol being an isomer of HQ) at particular pH's. This has been seemingly well known in the industry for a long time (and the couplers produced by the agents used to produce 'stain' were well investigated too), but never percolated out to the popular press, who instead seem to have preferred to persistently publish questionable re-inventions of the wheel.