Passage Summary: Camera companies love to brag about how sharp their lenses are, but the author thinks this is pointless because the film inside the camera isn't good enough to show all that extra detail anyway.

Conclusion: Differences in lens resolution between modern cameras are not significant for the purposes of practical photography.

Reasoning: Modern lenses are so high-quality that they project more detail than photographic film is actually capable of capturing and displaying in a finished image.

Analysis: This argument relies on a 'bottleneck' logic, assuming that because the film is the weakest link in the chain of detail, the lens's superior capabilities are wasted. To make this argument hold water, the author must assume that there isn't some other aspect of 'practical photography' that could benefit from that extra lens resolution. For instance, if a photographer wanted to enlarge a tiny portion of a photo, that extra lens detail might suddenly become very relevant regardless of the film's overall limitations. Look for an answer that bridges the gap between the film's technical limits and the broad claim that these differences are 'irrelevant' for all practical use.