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Due to a screw-up on my part, I need a high contrast paper developer. The neg has lots of density but is very flat. I'm comfortable mixing my own, so I need to be pointed in the right direction.
Variable contrast paper (Ilfobrom), contact printed. (yes, I have all the VC filters, I'd like more contrast.)
Thanks
very much
John
Ilford ID-14 gives almost a Grade more contrast with many papers.
ID-14 High Contrast Press Developer
Metol 1.5 g
Sodium Sulphite (anh) 50 g
Hydroquinone 12 g
Sodium Carbonate (anh) 37.5 g
Potassium Bromide 2 g
Water to 1 litre
For maximum contrast use 1+1, lower contrast 1+3
I used to use this back before VC papers were re-introduced in the 70's, it worked well with Ilfobrom & Ilfospeed graded papers,
Ian.
Ian,
In this thread you say the Sodium Sulfite should be 50 g and dilution of 1+1 for max contrast. But in two other threads where you write about ID 14, you refer to the sulfite as 75 g and the working strength as full strength:
http://www.apug.org/forums/forum216/...ral-tones.html
http://www.apug.org/forums/forum222/...developer.html
You're the best source I've found on so many various formulae so I'm just looking for the final word.
Thanks!
Quote:
Originally Posted by IanG
My mistake your quite correct. It should be:
ID-14 High Contrast Press Developer
Metol 1.5 g
Sodium Sulphite (anh) 75 g
Hydroquinone 12 g
Sodium Carbonate (anh) 37.5 g
Potassium Bromide 2 g
Water to 1 litre
For maximum contrast use Full Strength, lower contrast - 1+1, 1+3
The Formula was published by Ilford in 1930/40's Ilford Manuals if Photography.
Ian
Hint:
Hydroquinone increases contrast.
Potassium Bromide is a restrainer. Slows down the action of the developer, especially on areas that received minimum light. Some effect on contrast.
Sodium Sulfite is a preservative. Does not effect contrast.
So, choose a developer that has a lot of hydroquinone in it's formula.
The "Darkroom Cookbook" lists a few high contrast developers.
Gem, ID-14 gives higher contrast than Agfa 108 which is listed in the DCB, the other dev listed Edwal 120 won't give neutral tones due to the Pyrocatechin.
The level of Sulphite does have an effect on the contrast.
Ian
Ian,
Check the formula for Ilford ID-11.
12 gms of Hydroquinone and 50-75 gms of sulfite.
To me, that represents a developer that is high in hydroquinone and low in sulfite.
Exactly the point I was attempting to make.
Excuse the senior moment.
I was referring to Ilford ID-14, not ID-11.
Haven't had my first cup of coffee this morning.
Ilford ID-20:
Metol 3g
Sodium sulphite (anhydrous) 50g
Hydroquinone 12g
Sodium carbonate (monohydrated) 62g
Potassium bromide 2g
Water to make 1 liter
Gives neutral tones. Dilutions: 1+4 for low contrast, 1+3 for normal contrast, 1+2 for high contrast, 1+1 for very high contrast.
I believe you could increase the contrast even further by using it undiluted, though I haven't tried this myself.
This is my current print developer. I dilute it 1+3.
ID-20 isn't a High Contrast developer. I use it's PQ variants ID-62 & the warm-tone ID-78. Coincidently that's not the correct Formula.
ID-14 gives almost a full Grade more Contrast with Bromide, & Chlorobromide papers.
Ilford ID-20:
Metol 3g
Sodium sulphite (anhydrous) 50g
Hydroquinone 12g
Sodium carbonate (anhydrous) 60g
Potassium bromide 4g
Water to make 1 litre
Ian
Viad,
Compare the formulas for ID-14 and ID-20.
The only difference is the additional 1.5 gms of Metol in the ID-20.
Both developers contain 12 gms of hydroquinone. That's what makes them high contrast developers.
My idea of a high contrast developer is one that produces very dark rich blacks, used on a paper that has a bright white base. Amidol would be my choice for a high contrast developer.
It is the ratio between the Metol and Hydroquinone that determines contrast. A 1:7 or better ratio is typical of high contrast developers, as noted in the ID-14 formula which is 1:8.Quote:
Originally Posted by Vlad Soare
Ian, I have so far seen two different formulae for ID-20. The first is the one you mentioned (which, incidentally, is exactly like it was given to us by our teacher years ago). The second is the one I listed above.
I have no way of knowing which one is really the "correct" one, as I have no access to any official Ilford publication. I'd really like to know which one is the original, so if you happen to have strong evidence in favour of your version, I'd appreciate if you could confirm it, just for the sake of my curiosity.
For the time being, not having any strong evidence in favour of one or the other, I'm more inclined to use mine, for a subjective reason. 62g of sodium carbonate monohydrate is half a mol. I don't think it's a coincidence. It seems to me that the amount of 62g was first chosen because it represented half a mol, and later on it was probably rounded off to 60g just for the sake of simplicity (those two grams missing having probably no practical effect at all).
This tiny detail (which I agree is not evidence per se) makes me regard my version as more "genuine".
There's a big difference in the amount of potassium bromide, however. I don't know how to explain that. Could it have anything to do with the hydration state, which none of the formulae mentions? Maybe, though I'm not sure whether it would make such a big difference. I don't know. I'd appreciate any information on this matter.
The version I've given is the only one published by Ilford in numerous of their own publications, (I have at least 6).
The other may originally be from The Photo Lab Index, other books copied their formulae which were riddled with errors. They constantly mis-assume the wrong type of Carbonate, Monohydrated, anhydrous or Crystalline, or made conversion errors. Most US sources of Formulae are less reliable and one of the worst is Suzuki's website. The 3rd Edition of The Darkroom Cookbook is excellent and the only book I'd recommend.
The PQ version of ID-20 is the basis of some commercial Ilford developers, although usually Sodium Carbonate is replaced by Potassium Carbonate & Sodium or Potassium Hydroxide to allow more concentrated solutions.
Find a copy of the Ilford Manual of Photography, best are 1960's editions as they have the PQ developers as well, you'll find ID-62 there, or LFA Mason, Photographic Processing Chemistry, (Mason was head of Research at Ilford)
Ian
Quote:
Originally Posted by IanG
Hi ! I have found the Book of Ilford Formulas !!
This is the link: http://www.photomemorabilia.co.uk/Il...3rdEdition.pdf
You can search the original formula of ID-20.
This is brilliant!!! Thank you!Quote:
Originally Posted by Gabriele1971
Concentrated versions of all kinds of options will yield higher contrast IF the paper itself is capable of it. So will longer development times. No rocket science here.