Having identified the exact time frame when pits appear and their initial detected sizes, we sought to investigate whether the locations of their appearance could be deduced based on optical signatures associated solely with the formation of the passive layer. To achieve this, we employed a procedure conceptually similar to pit detection. In the first step, we collected normalized optical images starting from the OCP exposure up until the very last frame before pit formation (Figure ), followed by per-pixel temporal decomposition (Figure ). In contrast to the pitting detection results shown in Figure , the evolution of normalized intensities in Figure does not exhibit striking differences in behavior. Instead, all curves follow a consistent trend, with normalized intensities fluctuating within a narrow range of 98% to 102%, showing a slight overall decrease.