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Rodinal is the oldest photographic developer still in production today.

Rodinal is AGFA’s trademark name for a concentrated film developer formula, patented on January 27, 1891, by Dr. Momme Anderson.


The Developer has gained an extraordinary reputation quite quickly, and it became widely used as a film and paper developer.

After many years of being on the market, many people started using smaller and more compact cameras. Rodinal’s popularity suffered a little because of this, since film in those days had very coarse grain, and Rodinal made it show. Rodinal is not a fine grain developer! As films became finer grained, the popularity of Rodinal gained again. Compared to fine grain developers, Rodinal may show more grain, but it will show a greater perceived sharpness. Rodinal, in gerneral, produces great brilliance and great tonal gradation, with high perceived sharpness.


The nature of Rodinal to produce more visible grain structures, is because it doesn’t dissolve the silver grains, nor does it soften the edges of these grains. Compared to fine grain developers, the sharpness of Rodinal is naturally higher. When sharpening the scanned images of a fine grain developer, on many occasions, the grain will look pretty similar to that of the Rodinal developed image.  To me, at the end of the day, the difference between a fine grain developer and Rodinal is not big enough. For everyday photography, I choose Rodinal since the images will require less artificial sharpening for print, the developer is more economical, and there is no smeared or soft grain look. My biggest gripe is irregular grain structure, which is a film issue and not one of the developer. Besides, in print, much of grain visible in smooth and even tones gets reduced.


AGFA was bought out by A&O Imaging Solutions in 2005, and again to Connect Chemicals in 2008.

Today the product is either sold as AGFA branded Rodinal made by A&O, as R09 One Shot (by Connect Chemicals) or as ADONAL (by ADOX). I import the the “R09 One Shot” by Connect Chemicals. These are all exactly the same recipes! Its hard having to explain this to people! They take one look at the bottle, and then say, “we want the real Rodinal” ...well it doesnt get more real than this, or the other options above. The real AGFA product of 10 years ago is not the same as todays product, EXCEPT with regards to the formula of the actual concentrate developer.


Rodinal is used as concentrate, one shot developer. One can dilute it at ratios of 1:15, 1:25, 1:50, and 1:100.

The most common dilutions are 1:25 and 1:50, but people have had great success with 1:15, 1:100, and even with 1:200 or 1:300!  Because Rodinal is a One-Shot developer, it’s best to mix the working solution right before the developing process, and then throws out the used solution as it exhausts quickly. Rodinal in a working solution will only last a few hours, so keeping the developer in concentrate form is imperative.


Rodinal is a high acutance developer. What that means will be explained now... the definition of acutance is basically the “sharpness” of a photographic image. While acutance does not to refer to real resolution, what it deals with is fine detail contrast and edge contrast. Basically its a derivative of brightness between differently bright items with respect of the proximity of each other. This effect can be artificially recreated by using the USM tool, and applying an increased % of sharpening (basically an increase of contrast) over a wider radius,
in most cases in the form of a radius of pixels. On the right is an image that illustrates how increased edge-contrast can increase acutance or perceived sharpness.

The obvious effect of this is that halos start appearing in the difference in brightness is great, and if the increase of contrast is too high. Its very difficult to achieve such results with Rodinal. The results are more natural, and I have not encountered any halos besides with stand developing using Rodinal. This edge sharpness contributes to acutance, together with the more pronounced grain structure of the film when using Rodinal. Since Rodinal doesn’t dissolve the silver, or soften the grain crystals, the perception is that it looks sharper. It goes almost hand in hand;  well defined grain structures with harder edges looks sharper, and smoother grain with softer edges seems softer.


The higher the dilution of Rodinal, the greater the edge effect becomes. This is what happens. The less exhausted developer in low density areas of the negative, diffuses across contrasty edges, and develops them further. (This has become known as the adjacency effect) Also, the developer in the densest areas exhausts quicker than in less dense areas. This prevents dense areas from overdeveloping. While the dense area development slows down, less dense areas continue developing.  The result is an image with highlights protected by developer-exhaustion, and full shadows that continued to develop. In that sense, Rodinal will act as a compensating developer. This happens only when using a solution of 1:50 or higher.


The adjacency effect, or edge sharpness for that matter, can be controlled by the developer dilution and also by the agitation technique used. Also, grain can be slightly subdued by agitating less, in terms of time used to agitate, the amount of intervals used, and also the aggressiveness of the agitation.


Some people often use a technique called stand development... or semi stand development.

Rodinal is quite good for such developing. What it entails is developing your film for an hour or two, by just letting it stand, with no agitation. Semi-stand will entail a gentle inversion every thirty minutes. This often shows pronounced adjacency effects, with result that certain high contrast areas have halos. Over all the results are very cool, but it does require a bit of practise to get right. For starters, everything needs to be at room temperature! If your developing solution is slightly warmer than the outside air, or the developing tank temp is any different, the risk that micro thermal currents inside the tank cause uneven development, is very high. Hence, the gentle inversion of a semi-stand develop, often helps prevents uneven development. My first attempt failed at getting the results one wishes for, but they were very interesting! Uneven development in those were clearly visible.


Over all, Rodinal is amazingly popular, and it is so for a very good reason!

I definitely enjoy using Rodinal, and it’s something I will always have a lot of (just in case, hehehe)

 
Write up:
  1. High concentrate developer

  2. Long lasting in concentrate form

  3. Economical

  4. One-shot developer

  5. High acutance

  6. High edge sharpness

  7. Can be used as compensating developer with specific dilutions

 Development Data by www.digitaltruth.com (9 pages)http://www.digitaltruth.comhttp://martinzimelka.com/DevTables/Digitaltruth%20Photo_Rollei_IR400.pdfshapeimage_14_link_0
 Manufacturer’s Datasheethttp://martinzimelka.com/DevTables/Rodinal.pdf