The antonyms for the phrase "captured on film" would be "missed on film" or "uncaptured on film." This could refer to moments that were not captured due to technical difficulties, the photographer not being present or available, or simply being out of range. Other antonyms could be "invisible on film" or "non-existent on film." This could refer to moments that were not captured because they simply did not occur or were not visible to the camera. Whether intentional or not, the antonyms for "captured on film" highlight the importance of timing, circumstance, and the ability of a photographer to be in the right place at the right time in order to capture the moment.