Developer experiment

[Shen45]

Over the past few days I have been formulating a couple of different developers with the hope of acheiving a better tone gradation from my Efke film. [PL100].

I test using BTZS methods and shoot that way as well and found that D76 1+1 gave a very good result but the grain was a bit smooth for my liking. When I say that I mean it felt not quite as sharp as it could be.

I am not a photographic chemist but a little bit of research indicated the pH of D76 is about 8.5 so I used that pH as a lowest level pH to work from. According to my pH meter the store bought D76 was 8.5.

I looked at the 2/5 ratio of Metol/Hydroquinone and decided on a slightly higher Metol to Hydroquinone but with the hope of retaining the D76 superadditive affect.

I have always liked the tonal gradation with formulas based on Sodium Carbonate but they are usually not fine grained.

I found a couple of old Agfa developer formula that used Potassium Carbonate instaead of the Sodium Carbonate and i did find [subjectively] they had a slightly different look to the SC version. I retained Borax because it is supposed to be a bit softer working on the grain and gave it a "touch up" with the Potassium Carbonate.

D76 normally has about 2 grams of Borax to the litre but also has 100 gms of Sodium Sulphite. I increased the Borax and added the Potassium Carbonate to lift the pH to an active level because the formula I have arrived at has only half the Sodium Sulphite.

Here is the formula I put together.

Mix in the order given

700 mls [120 F]

2.2 gms metol
50 gms Sodium Sulphite
6 gms Hydroquinone
3 gms Borax
2 gms Potasium Carbonate [Substitute sodium carbonate if you need to]



Water to 1000 mls

Final pH about 8.9

For my initial tests I halved all the above to make 500 mls

With Efke 100 try 1+1 @ 70 F for 7 minutes. Rate the film at 50 iso.

Of course determine your own film speed if this works for you.

My initial test images are very promising.

[IanG]

In some ways the addition of the small amount of carbonate is akin to using Sodium Metaborate (Kodalk) instead of Borax, as in DK76.

I'm very surprised your shooting PL100 as 50 EI, because that's what I've been shooting KB25/R25 & PL25 at for many years, in various developers.

You might try Adox Borax MQ, it gives better sharpness, speed, tonality an marginally finer grain than D76/ID-11. It's a variant of the D76/ID-11 type developers, and very similar to the developer that was used for ASA/BS tests.

Metol 2 gms
Sodium Sulphite 80 gms
Hydroquinone 4 g gms
Borax 4 gms
Potassium Bromide 0.4 gms
Water to 1 litre

Ian

[Shen45]

Hi Ian,

So many developers and so little time. That formula looks promising as well. I may try it tomorrow.

Steve

[Shen45]

Hi Ian,

The iso of the film is not a concern as I use BTZS and depending on the scene it can be 32 - 90 iso and then each sheet is developed according to the data from ExpoDev the BTZS software used in the field on a palm pilot.

Testing is done with 4 - 5 sheets of film exposed under an enlarger at a determined EV rating and then the 21 step wedge is read into WinPlotter and a film file can be exported to the palm. The incident or spot meter is only used to obtain an EV reading of the subject brightness range and then the exposure is calculated based on the capabilities of the film developer combination being used relative to a known value of the paper's capacity to handle again a known tested range of tones.

I gave an iso of 50 as a starting point for anyone who may like to shoot a sheet of film just as a trial. On the WinPlotter software that is the tested iso with that developer based on a negative for a diffusion enlarger using Ilford Multigrade Pearl with a grade 2 - 3 filter ---- on my system.

Steve