There is no optical relationship between the aperture and the type of optical corrections needed/forced for the wide end of MILC zoom lenses. There is, in some cases, a difference in apparent focal length whereby Canon is patenting the focal range of the lens incorporating digital corrections rather then the 'true' focal length which has mechanical vignetting at the wide end in addition to ample distortion. That's actually why the image height at the wide end is not sufficient to cover a FF sensor, and led to CRguy and others erroneously suggesting RF (full frame) lens patents were intended for APS-C sensors.But it doesn't really change my question regarding the wide-end lens-correction needed in post, and how to interpret F- and T-stops in the wide end for such designs...
F-stop and T-stop have never been directly correlated, although obviously T-stop will be slower than f-stop. Convention is that cine lenses are specified for T-stop and still lenses are specified for f-stop. The measured T-stops of mirrorless lenses are in a similar range to those for DSLR lenses, and as before the consumer grade lenses tend to have a slower T-stop relative to f-stop than the L-series lenses.
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