This may look odd, as this thread died away a decade ago, but I do not want to start a new one with a similar title. Since the beginning of July 2017 I was doing my own "taming" of Rollei Retro 80S, that is, achieving something close to pictorial contrast negative. I'd like to share my observations that I think are new, so far just as a statement, and hear some feedback, and perhaps I would need more experiments just to answer the questions.
So, here goes. I think the most important observation is that this film is not a pictorial film at all, and should be firmly placed in the category of high contrast document films and for pictorial contrast should be developed in specialized ultra-soft working developers. There are, obviously, quite a few known solutions for the latter. It would be a grave mistake to send this film to a lab, or use any "normal" developer, unless you aim at getting a high contrast negative. The second most important observation is that this film's emulsion is extremely thin, and as such does not benefit at all from agitation during development, less initial 30 seconds. Agitation every 30 seconds during 15 min, and agitation once for 30 seconds for a subsequent 15-min stand development gives literally the same result. For the same reason, this film completely fixes itself in 2 minutes continuous agitation (fresh Ilford Rapid Fixer) and also dries flat very quickly, under 10-15 minutes, without any forced air flow. All this refers to 35 mm film, I have not tried 120 so far.
As one may expect and that indeed I observed, two bath developers wherein the first bath contains the developing agent and the second the alkali do not work well for this film due to too little solution absorbed in a thin layer and even though the reduced contrast can be observed, the effect is marginal. For example, two bath version of the Beutler formula works better than a single bath, but the resulting contrast is still too high. However, two bath developer of Jean Fage gives a very nice result at 7+6 minutes at 20 C. A couple of other developers that I tried, known to work well in stand development, such as Caffenol C-L and Paranol-S 1:100 (a clone of Rodinal) give visually very nice pictorial negatives at 30 min stand development at 20 degrees Celsius, awaiting curve calculations.
For even lower contrast, I have been experimenting with another developer, called H&W Control (
http://jdelisle.net/develop.html), with a high concentration of phenidone and a very low concentration of hydroquinone. While the fresh developer is probably the best solution I found, I am trying to work out a modified version with a longer shelf life, and this project is unfinished. As a control experiment, H&W Control produces unacceptably low contrast with Kentmere 100 or Ilford FP4, while it is usable for Ilford Pan F. Contrast of this developer can be varied with amount of hydroquinone, which is always very small compared to typical PQ developers.
The other developer that showed initial promising results was #101 from the Jacobsons' book "Developing". It is based on an old patent and contains only CD-3, sulfite and carbonate. It can be modified into a 2-bath version with a usable shelf life, but again this is a work in progress.
For every film/developer combo tried I included two shots with transparent Stouffer wedge, but it may take a while to convert those to curves. I realized somewhat late in the project that this is a better way to do comparisons than shooting outdoor scenes of high contrast.