| Rollei RPX25 (25 ISO) | Adox Adonal |
| Format: | 120 and 35mm |
| Exposed at: | 25 ISO |
| Developer dilution: | 1+100 |
| Development time: | 60 minutes |
| Temperature: | 20°C |
| Agitation: | 30 seconds of agitation and 2 inversions at the 30-minute mark |
What Can Be Expected from This Development?
Rollei RPX 25 is a classic-grain film and Adonal is a non-solvent developer. One can therefore expect images with strong acutance and sharpness.
As expected from such a low-speed film, RPX 25 delivers excellent definition. The grain should therefore be virtually invisible, even in 35mm. However, one may wonder whether using a highly diluted non-solvent developer could make the grain more noticeable.
As for tonal rendering, one can expect contrast. This is due both to the film’s limited dynamic range and to Adonal’s characteristic tonal curve (essentially identical to Rodinal).
RPX 25 and Rodinal diluted at 1+100 form a combination with an excellent reputation for landscape photography.
One can notably expect a “halo” effect around objects. While this effect is understandably undesirable for scientific applications (as it distorts measurements), it can be quite appealing in landscape photography.
Fine Detail and Exceptional Definition
This is exactly what one expects from a film of such low sensitivity, and RPX 25 does not disappoint. The photograph below was taken on 35mm film.
It is worth noting that the resolution is not only exceptional, but also accompanied by a distinctly “sharp” grain structure that enhances object contours remarkably well.
A Visible Halo Effect
Although it is not immediately obvious, the halo effect is definitely present and adds a subtle but pleasing enhancement to landscape photographs.
Limited Dynamic Range
This is the drawback of low-speed films. It is impossible to recover detail across the entire image outdoors. There will always be areas of the negative that are completely black or completely white.
However, with the negatives I obtained using a 1+100 dilution, I noticed with some amusement that this flaw appeared less pronounced than what I have encountered with medium-speed tabular-grain films. At the very least, the transition from detailed areas to areas without detail feels more gradual with RPX 25.
Additionally, I have the impression that there is room for overexposure in order to recover more shadow detail without sacrificing the sky, while also achieving richer tonal rendering.
Imperfect Results
Perhaps sunny weather is not particularly suited to this combination, or perhaps I still need more experience with exposure settings, but I struggled to achieve a rendering that fully satisfied me. Further experimentation is needed.
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