The popular online lens rental company will be applying its famously thorough still photo tests to cinema lenses.
It’s hard for filmmakers to remember this, but 4K isn’t actually that much resolution to a photographer. 4K video is something like 8 megapixels, which is nowhere near top of the line resolution for modern photography. 1080p, which many still shoot and most networks still broadcast, is only 2.3 megapixels. Compared to photographers who regularly shoot 30-50 megapixels, these are tiny numbers. While there are a lot of demands on a cinema lens (light weight, consistent focus, parfocal zoom), high resolving power has never been the top priority.
8K and other high resolution cameras are becoming common enough that rental houses have to accommodate that market with more detailed information.
From:: No Film School