Rodinal
High Grain & Contrast using Rodinal
From unblinkingeye.com
By Ed Buffaloe

Rodinal is Agfa’s trademark name for their concentrated film developer formula, patented by Dr. Momme Andresen in 1891.  It is the oldest continuously-produced developer formula in the world. Within twenty years of its invention Rodinal was so widely used for both film and paper that it merited its own listing in Bernard Jones’ Encyclopedia of Photography, and  for a time it became a generic term for any formula that used p-aminophenol. Rodinal has a very well-deserved reputation for brilliance, gradation, and sharpness.

A number of “rodinal” formulas have been published over the years. Agfa’s has always been proprietary, but is so cheap and reliable that photographers have rarely mixed “rodinal” themselves (though Photographer’s Formulary now sells a version). Essential ingredients are the developing agent paraminophenol hydrochloride, the preservative potassium metabisulfite, and the alakali (or accellerator) sodium hydroxide.  The usual formula is 3 parts potassium metabisulfite to 1 part paraminophenol, dissolved in 10 parts hot distilled water, to which is added, drop by drop, only enough of a saturated solution of sodium hydroxide to clear the precipitate which forms.  [Please see the darkroom safety cautions in Mixing Developers, and handle sodium hydroxide (caustic soda) with great care.] Dilutions for this version are in the range 1:20-25. Once diluted with water, Rodinal does not keep.

Paraminophenol is a developing agent with unique properties: it produces little fog and no stain even at high temperatures, is relatively fast-working, is less temperature-dependent than other agents, can be mixed and stored in very high concentrations, and retains developing potential even at very high dilutions. The potassium metabisulfite preservative is at a low enough concentration that it has no solvent action on film grain. In high concentrations, sodium sulfite (the most-used preservative in photographic formulas) is said to literally eat away the sharp edges of silver grains in the developing emulsion. The dissolved silver is then available to be plated back onto developed silver grains in a process known as physical development. Physical development tends to blur the sharp edges of silver grains in the emulsion, reducing perceived sharpness.  Rodinal avoids this drawback.

Rodinal is not a “fine-grain” developer. When miniature cameras first appeared, Rodinal fell out of favor because the early 35mm films were very coarse-grained, and looked it when developed in Rodinal.  But Rodinal regained its popularity as the grain structure in modern emulsions became finer and more consistent.  Conventional wisdom has it that, with Rodinal, whatever grain structure is inherent in a film’s emulsion will be retained in the developed negative.  Rodinal negatives may sometimes look more “grainy” than negatives developed in the so-called fine-grain formulas, but they also have greater perceived sharpness.

Mixing Rodinal and Xtol
by Sam Elkind

I read with interest the Nov 28th exchange on the BW Film Developing forum about Vit C developers and the Rodinal variation.  On that forum, I have on occasion mentioned a blend I use that gives excellent results with (at least) Tri-X, Delta 100, Delta 400, and Verichrome, in both 135 and 120 formats. I think people have an initial reaction that the idea sounds preposterous.
 
The blend uses both Xtol and Rodinal.  The origin for me was that Xtol results were too flat, while Rodinal results were too grainy (no surprise). A couple of years ago, I was searching for an ideal developer and after some tests I settled on this blend.

Following is the result of my testing (quantities set to my 500 mL tank):

Xtol = 100 mL
water = 400 mL
Rodinal = 4 to 5 mL
 
Times @ 24 degrees C. are:

Tri-X (200) = 9 minutes.
Delta 100 = 10.5 minutes.
Verichrome = 8.5 minutes.

This blend may be useful to you and perhaps others.  I think you will find the grain is quite acceptable, even in 35mm negs, and that tonality is attractive, especially in highlights.  In the context of the exchange on the BW forum, in which you made reference to Gainer's Rodinal variation, I thought you might find this combo of interest.



FILM EI Dilution 68° 70° 72° 75°
Efke KB/R-100 100 (1:100) 15 14 13 11
Efke KB/R-100 50 (1:50) 9 9 8.5 8
Efke KB/R-50 40 (1:50) 9 9 8.5 8
Efke KB/R-25 12 (1:100) 9 9 8.5 8
             
Agfa APX 400 200 (1:75) 14 12 10.5 9
Agfa APX 100 50 (1:50) 8 7.5 7 6
Agfa APX 100 100 (1:50) 12 11 10 8.5
Agfa APX 25 12 (1:100) 7 6 5  
Agfa APX 25 25 (1:75) 15 14 13 11
             
Ilford Pan F + 50 (1:100) 12 11.5 11 10
Ilford Delta 100 50 (1:50) 8.5 8 7.5 6.5
             
Kodak T-Max 100 50 (1:75) 10 9.5 9 8
Kodak T-Max 100 80 (1:75) 15 14 13 11.5
Kodak T-Max 400 250 (1:50) 10 9.5 9 8
Kodak T-Max 400 400 (1:50) 12 11.5 11 10
Kodak Tri-X 200 (1:50) 9 8.5 8 7


Rodinal contains a high-acutance, low-fog developing agent (p-aminophenol hydrochloride).  At the higher dilutions recommended here it gives a slight compensating effect and good edge effects. Agitation should be for 10 seconds once each minute. Times are for roll film in small tanks, optimized for printing with a cold light head.


From slonet.org

Rodinal with sodium sulfite provides more control and much shorter development times. Since Rodinal is a reasonably active developer and will produce VERY contrasty results with normal development, higher than normal dilutions and limited agitation, are needed to produce a normal contrast index.
The traditional spiral developing tank in which developer flows through narrow passages between layers of film creates serious problems for high energy developers when limited agitation and/or high dilution is used to control contrast. Special care is required with the agitation pattern, especially with 35mm film to avoid streaks from developer swirling through the sprocket holes. Several solutions have been proposed for a 35mm developing tank.
A 35mm technique which has, for me, provided the best results with the traditional spiral tank, was suggested by Bill Hoy of Bedford County, VA.

  • Use a tank at least twice the size needed for the number of reels you plan to develop.
  • Fill the extra space with empty reels, placing the film at the bottom of the tank.
  • Pour in just enough developer to cover the film, then simply invert the tank at the specified interval, draining the developer completely from the film.
  • After five seconds, reinvert the tank, reimmersing the film.
Presoak Tech Pan for 1.5 minutes in distilled water of the same temperature as the developer. I don't remember why a minute and a half, something in the distant past, but it seems to provide a more even development. It probably also lowers the contrast a bit since it takes time for the developer to displace the water in the emulsion.

Consider pouring the developer into the tank (already loaded with film) to be an agitation cycle, so carefully put sown the tank without further agitation. The remaining agitation is provided at 1 minute intervals with Bill Hoy's method described above. With these short development times, both the agitation scheme and interval have a major influence on negative contrast and density Because the limited agitation contributes to the lowering of negative contrast, it is the periods between agitation (similar to "water bath" development procedures) that supply the build-up of shadow detail.

My best results are obtained near 20 deg C, both the time AND agitation interval being critical to the shape of the curve. I have never tried temperatures less than 20 deg. and have read somewhere that the characteristics of developers significantly change with lowered temperatures. Perhaps someone near the arctic circle can contribute advice here.



 
 

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