Quenching Sphere of Action Model
Iodide shows a positive deviation to the Stern-Volmer model.
If static quenching were present, we would see the same deviation.
However, iodide does not form a ground-state complex with quinine.
Rather, at high concentrations, iodide is in such close proximity to quinine that quenching occurs immediately upon excitation. This process appears as static quenching would in a Stern-Volmer plot.