Keith Tapscott.
Allowing Ads
This formula is recommended by Kodak to produce extra fine-grain negatives than those processed with standard developers, albeit at some loss of film speed.
Has anyone ever tried this formula?
KODAK D-25
Low to medium contrast fine grain film developer.
Water, 125*F/52*C 750 ml
Metol 7.5 grams
Sodium Sulfite (anhydrous) 100 grams
Sodium Bisulfite 15 grams
Water to make 1 Litre.
Mixing instructions: Add chemicals in specified sequence.
Dilution: Use undiluted...
It's not really similar at all, (well not to any form of Rodinal)
The Sulphite content is more than ten times higher and the pH is close to 7 whereas old Classic/Rodinal must be nearer 9-10 (that's a very quick guess, but it should be roughly 11.8 before dilution).
It does show quite nicely how Kodak switched techniques though to high sulphite levels for fine grain
Ian
Actually Ron, it's a lessson on the extremes of a simple developer, one end is higher pH and acutance, the other with a low pH is very fine grain.
In the case of Metol the middle ground, as in most practical is D23. But the there are good reasons it's not used by many.
Ian
If you view the "triangle" of developer properties as flat, then by applying some new technology it can become effectively a "pyramid" bringing the points of the triangle closer in and making a developer that improves all 3 properties at once.
Buckaroo Banzai forever!
PE
Actually Ron, it's a lessson on the extremes of a simple developer, one end is higher pH and acutance, the other with a low pH is very fine grain.
In the case of Metol the middle ground, as in most practical is D23. But the there are good reasons it's not used by many.
Ian
*******
Having long been addicted to replenished D23, I tried D25 several times but it was just too soft, and mushy for my taste. Kodak does suggest using half the bisulphite; but I never tried it. D25's replenisher, DK-25R, however, is what I use to replenish my D23.
******John,
I'm interested in replenished developers, D23 being one of them. How do you ripen a new batch of D23? and how much replenisher do you use for each 80 square inches of film developed in D23?
Thank you,
Mike Sullivan
Sorry Ron, but I don`t see the connection between D-23, D-25 and Rodinal.
When you add other, more exotic ingredients, a point I have made elsewhere, you push outside this "triangle" and can get some vastly improved properties.
But you can also increase the complexity of finding a combination that works well or better.
John,
I'm interested in replenished developers, D23 being one of them. How do you ripen a new batch of D23? and how much replenisher do you use for each 80 square inches of film developed in D23?
Thank you,
Mike Sullivan
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?