Archived posting to the Leica Users Group, 2007/07/27
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Rodinal is an AGFA proprietary name for a highly concentrated developer that uses para-aminophenol (p-aminophenol) as its primary developing agent and potassium hydroxide as its activator (alkali). The formula is unpublished but can be replicated relatively easily. Fomadon R09 is similar; Photographer’s Formulary makes a version, Fotoimpex has Adolux APH09 and Calbe R09 is another. There are others and you can mix your own. I haven’t followed the 'what has happened to Rodinal since AGFA collapsed' story – maybe someone else can fill this in for us. Richard asked: >I was reading over the XTOL rant and wondered how does XTOL relate to >Rodinal. I have heard that Rodinal is a compensating developer. So >how similar are they. Rodinal is a much older formula I know. Xtol and Rodinal are not related chemically at all. There are some interesting formulae you can try that combine both p-aminophenol and ascorbate, which I have included below. Rodinal is a compensating developer, but only because it works well at very dilute concentrations. Development by-products that are released by the film include bromides, which are development restrainers. With most developers, the amount of developer around the film completely negates these bromides, but because p-aminophenol develops effectively at very low concentrations, the bromide restraint works effectively to proportionally diminish development. The pH of Rodinal is very high (very alkaline) and this is part of the reason for its activity at high concentrations and the graininess of films developed in it. Rodinal has a reputation for sharpness (more on this below). >Another question is Rodinal suitability for processing T-Max and >Delta films. So what say you all. Rodinal will develop any film. But tonality, an important component of B&W photography, is influenced heavily both by film and developer and the paper (or post processing if you print digitally from negatives). Rodinal has one tonal characteristic that limits its usefulness for me; it tends to lower midtones. With films like Tri-X this gives a beautiful ‘dark’ look that can work very well. It also works(ed?) well with the APX films. With flat-grain (T-Max) and epitaxial (Delta) monosize emulsions, Rodinal tends to apparently lower the midtones more (I say apparently because I haven’t measured it, but it looks like a proportionally greater effect to me), making tonality odd and generally less than optimal. Printers and scanner/photoshoppers of considerable skill can get around this (Ansel Adams produced beautiful work from HP5 or Tri-X in HC110 dilution B, or so he said, whereas both are poor F&D combinations that produce ‘soot and chalk’ tones even at normal CIs) but for most of us it just makes life tough. Rodinal is a particularly poor match for T-Max 100 (TMX). T-Max P3200 (TMZ) at EI 1000 or 1600 developed in Rodinal 1+50, on the other hand, is quite striking if you like HUGE grain, but again, the midtones can be a little problematic. I think most films that look good in Rodinal look better in dilute D23 (except Tri-X which I think needs a little hydroquinone with its metol and looks better in dilute D76). They all look better to me in Xtol. The other often overlooked factor associated with Rodinal is that it isn’t as *relatively* sharp as it is often made out to be. Anchell rates it slightly as having slightly higher acutance than dilute solvent developers, but I think that results from D76 1+2 are equivalently sharp and Xtol 1+2 or 1+3 looks sharper to me. Amusingly, D76 has no reputation for sharpness at all. When Anchell wrote about dilute solvent developers, I don’t know if he’d experimented with low-sulfite developers using ascorbates. I'm working from memory here. Beutlers, some of the Crawley formulae and some pyrocatechin developers are also MUCH sharper (Anchell’s book discusses this at some length and it was summarised by Mark Rabiner here: http://leica-users.org/v21/msg10232.html). Neither dilute D76 or Xtol will produce the loss of emulsion speed that highly dilute (1+75 and above) Rodinal will typically display. Remember that very high sharpness developers often don’t have the best tonality. >Rodinal makes no attempt to hide grain. It actually gives grain sharp >edges and increases the contrast of the negative. X-Tol seems to >increase contrast as well while minimizing grain. I’m trying to be explanatory rather than contradictory here; contrast in B&W film is controlled by exposure and development. While some developers are inherently more contrasty than others, with modified exposure and development time, almost any developer (and certainly any standard developer) can be used to develop film to a given contrast index (CI). How it looks will change, however, because the F&D combination will have a different shape curve (after all, the CI is just the average slope of the density curve). What you see with both dilute Xtol and Rodinal are adjacency effects – they look contrasty because of their acutance, which tends to produce highly defined lines where widely spaced tones meet in photos. >I use X-Tol for most of my 35mm to give me the finest grain. I recommend this strongly. Xtol has the best combination of film speed, sharpness, and grain structure of any developer I’ve seen. For 35mm films, the only reason to use anything else is a lack of ability or willingess to use distilled water. It works remarkably well with almost all films. >The other advantage to using Rodinal is the convenience of having a >super long lasting concentrate always handy without the worry of an >expired, powder developer when I haven't developed film in awhile. It >works just fine with any film I've ever used, even the Ilfords you >mentioned although I now prefer the Fuji films to just about anything. If what you really want is an everlasting concentrate, Rodinal is very good. My first samples of JB9 (see the Xtol rant) show no sign of oxidation or loss of potency after ~2 years and might be a good substitute for those who want an ‘everlasting’ concentrate with the advantages of ascorbates. PC-TEA is also pretty much indestructible. Classic Rodinal formula Solution A Water, 125F/52C 750 ml p-Aminophenol Hydrochloride 100 g Potassium Metabisulfite 300 g Cold water to make 1L Solution B Cold Water 300 ml Sodium Hydroxide 200 g Cold water to make 1L Mixing instructions: Add chemicals in specified sequence. Always use cold water when mixing sodium hydroxide due to risk of heat reaction. Unlike many other two part developers, you must mix both parts together to make the concentrated solution. In The Film Developing Cookbook, Troop and Anchell suggest the following sequence for making the concentrated developer: Allow Solution A to cool until a precipitate forms. Mix Solution A in an iced water bath at this stage, then slowly mix in Solution B while constantly stirring, first adding 280ml of solution B, and then adding the remainder until the solution suddenly turns dark. Follow this by adding the last drops of Solution B very slowly. Always wear gloves and protective goggles when mixing sodium hydroxide. Dilution: 1+25, 1+50, 1+75, 1+100 and others. It’s interesting that hydroxide + bisulfite produces sulfite and that a litre of 1:25 strength Rodinal probably has about 14g of Potassium Sulfite in it. This provides about as many sulfite ions as 10 grams of Sodium Sulfite. Rodinal variations Some photographers dissolve 25-100g of sulfite in the diluting water prior to adding the Rodinal. This seems like a completely counterproductive move to me. 4g/L sodium ascorbate makes Rodinal more active, finer grained and partly addresses some of the tonal issues. Don’t use ascorbic acid – it will decrease the pH enough to kill the developer. If all you can get is ascorbic acid, mix 2 parts ascorbic acid with 1 part sodium bicarbonate (bicarbonate of soda) in some water and wait until the fizzing stops to convert it to ascorbate. Pat Gainer says that adding ascorbate sometimes causes significant fog – this figures since the pH of Rodinal is high enough to allow the ascorbate to initiate development on its own (rather than acting in synergy with p-aminophenol). If you experience fogging, Pat Gainer says that 1g/L borax buffers the pH enough to prevent fogging. He goes on to add that 1g/L borax in plain Rodinal decreases grain and fog. Plenty to try here. Patrick Gainer’s PCK 10 grams p-aminophenol.HCl 20 grams ascorbic acid 30 grams sodium sulfite 10 grams sodium hydroxide 1L water Mix in order. As soon as you stir in the sulfite, you will see the same sort of precipitate that you see when mixing Formulary Rodinal. Add the 10 grams of hydroxide. Use diluted 1+9. I haven’t tested this, but it should work well. Sam Elkind’s insane Xtol/Rodinal hybrid Xtol = 100 mL water = 400 mL Rodinal = 4 to 5 mL Sam says 9 minutes works well for Tri-X @200 @ 24C. I’ve only read this; I haven’t tried it. People will try anything after all. It should work, but it would be costly and probably isn’t any significantly better than PCK. Again, I hope this is informative and useful. Much of this is derived from tests, but much of it is also just my opinion. If you have a long-lasting, almost physical love for Rodinal, please don't worry about defending your developer of choice - I can see why you like it. I just don't. Marty -- We've Got Your Name at http://www.mail.com! Get a FREE E-mail Account Today - Choose From 100+ Domains