This is a good development for video Canon EF lens users. I use 6 EF lenses with my 60D for video.
An article from Photgraphy Bay talked about a new Canon patent:
“Anyone who has shot video with a Canon DSLR recognizes that smooth iris pulls are impossible while recording with Canon’s EF lenses. In one of the more interesting patent applications of late, Canon revealed that it is working on new lenses with aperture rings for adjusting aperture settings during video capture.
The new lenses with aperture rings utilize electronic control of the lens diaphragm rather than a mechanical aperture ring of yesteryear.
What’s not entirely clear is whether or not the aperture adjustments via the lens ring will offer step-less iris pulls. This feature is not addressed in the patent application. However, the presumption is that a new lens design for iris adjustments during video capture would offer much smoother changes than the terrible 1/3-stop clicks we get now out of the adjustments from the camera body.”
Read the full article at their site.