An M/Q developer is one with two reducing agents (developers). The standard M/Q developer over the past 100 years has been Metol & Hydroquinone, and when combined, bring about what is referred to as 'superadditivity'; the Gestalt effect of the result being more than the sum of its parts. Superadditivity derives from the characteristics of each reducing agent. Metol is a slower acting reducer with a fairly long developing life, whereas hydroquinone is more energetic but loses steam in short order when used alone, respectively. When added together, they create the superadditivity by combining their mutual assets, creating a energetic and long lasting developer. Probably the most used of these developers using Metol/Hydroquinone is Kodak's D76 (negatives) & Dectol (prints).
My argument against using any M/Q developer today is simple. It isn't needed with modern films for the vast majority of developing needs. The superadditivity element can be mimicked by dilution control using a Metol only formula. By controlling the developing through dilution allows for consideration to the choice of either a very energetic development (superadditivity) or semi-compensating development, when highlight control is needed for contrasty lighting conditions. This is important.
My argument only works of course, with mixing your own developers, not pre-packaged developers. The hydroquinone is already in those developers. I cannot repeat enough times that mixing your own developers, and fixer, is not only simple but very cost effective. Recent price analysis of current chemical pricing shows that an outlay of $50 (give or take) buys enough chemicals to develop negatives for six months to a year, depending on how aggressive a shooter one is. Mixing is as simple as pouring the pre-mix into a vessel of water. The Bisquick analogy is fitting here, as it is made up of three dry ingredients, as a developer is. It does require a cheap gram scale. I bought my digital scale for $17.50 online and it gets down to a tenth of a gram. Trust me on this issue. Visit Bostick & Sullivan or Photographer's Formulary and look up the prices for the chemicals I will be listing below.
There are two formulas I used for years that covered every need for developing negatives. Both are Metol only formulas, and both can be used in various dilutions for very good results. Beutler 105 is considered a semi-compensating developer, meaning it can hold in the detail in bright highlights, much like pyrocatachen, which is a fully compensating developer. The second developer is D23, considered to be a fine grain developer. Formulas below;
Beutler 105;
Water (@110 deg) 750 ml
Metol 5 g
Sodium Sulfite (anhydrous) 25 g
Sodium Carbonate (anhydrous) 25 g
Water ~ t/m 1000 ml
Use: 1:10 {ISO 125 ~ 8 min} {ISO 400 ~ 10 min}
D23;
Water (@110 deg) 750 ml
Metol 7.5 g
Sodium Sulfite 100 g
Water ~ t/m 1000 ml
Use: Undiluted (normal) {ISO 125 ~ 8 min} {ISO 400 ~ 8-10 min}
The above formulas are in their original form, and both will work well, however, both can be altered by dilution that can accommodate almost every need. The D23 formula is an offshoot of the Beutler formula. When increasing the sodium sulfite by that degree, it becomes a sort of reducing agent, as well as the preservative, which is its normal function. By eliminating the sodium carbonate makes it a better fine grain developer, although Beutler is also a fine grain developer.
By diluting D23 further; 1:1 or 1:2, which I have done, brings this developer more into the semi-compensating arena. I saved a severely overexposed negative by diluting D23 to 1:10, developing for over 20 minutes. I will be digging that negative out at some point to demonstrate how that came about. With Beutler, the dilution goes the other way; using it at 1:7 or 1:5 for more energetic development. The 1:5 mixture would be what we call "hot". That would be the route to negatives of the Log E 1.2 to 1.8 needed for hand coated printing in silver and platinum/palladium. Gum prints are a different matter and that will be another article to cover that.
Here is how the Contrast Index curve is affected by dilution. The example shows the Beutler
formula in three dilutions; 1:10 (bottom curve) 1:7 (middle curve) 1:5 (top curve)
As can be seen, the more dilution of Beutler the lower the contrast index curve. The most energetic curve is from the 1:5 dilution which is double strength of the original dilution of 1:10. For most of my salted silver images of the original portfolio I used Beutler at the 1:10 dilution, developing 20 minutes to reach a density range of Log E 1.2. I would have been better served altering that relationship to 1:7 for 15 min or possibly 1:5 for 12 or so minutes. I had not reached the evolution of that printing to have branched out with the testing for these two variables. I will be though.
Back to the two variables for development; Time & Formula Dilution. With dilution, the compensating quality of these two formulas decreases. Which is exactly why texture tests are so important. There is a very simple means of testing any given formula, with a specific lens (this is important) using a white bath towel. That would make a useful article, as this can be easily done with roll film as well as for sheet film.
The negative for the image below was developed in Pyrocatechin/Hydroxide formula. I have not brought this up yet. This is a fabulous formula, but care must be taken when using hydroxide as it is the most volatile of all photo-chemicals. A gram of it in a 1000 ml beacon of water will make the water boil. Hence due care is highly recommended. What the pyro/hydroxide formula offers is the highest acutance that can be obtained. Hydroxide provides that, as an accelerator. The emulsion side of the negative feels like a Bas Relief when you run your finger over the emulsion image. What is missing here is the original textural quality of a salted silver print. My attempts at scanning and digital manipulation for posting images basically sucks, on top of the red/green deficiency. My apologies.
Salted Silver Print ~ "Jerome House"
1986 ~ 5"x7" ~ Unique
Jerome, Arizona
No comments:
Post a Comment