Canon EF 100-400 f/4-5.6L IS Patent Pending

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I know well that (a) this does not prove that a new lens is around the corner and (b) it is supposed to be a more or less general solution to an optical problem rather than a specific lens design.
Having said that, the arrangement does look rather similar to the existing 100-400L, so it would appear that this is not some land-grab of a far-future crazy idea but something rather practical and therefore much closer to production.
The 100-400 is certainly a good candidate for that. There has already been plenty of speculation about an replacement. I don't know how long patents take to get approved and published these days, but if a factory-ready design existed, Canon would certainly hold it back until the patent was published.

 

[Lee Jay]

Despite the push/pull design... what's so bad about the current 100-400ß?

Really poor handling in multiple ways, poor performing IS, optical quality degrades a lot if the IS happens to be at a substantially off-center position when you shoot, mediocre corner performance, relatively slow AF compared to newer lenses, not diffraction-limited in the center wide open despite being f/5.6.

I'd really, really, really like to see a new high-pixel-density 1.6-crop camera with high-performing f/8 AF sensors, and a new 100-400L that goes with it that's designed to be dead-sharp wide open with a 1.4x TC on it on that camera (which could AF with it that way), and to have all that other stuff fixed. The ideal one would be f/4.5 at 300mm and have AF faster than the 400/5.6L while weighing the same, thus eliminating the need for the 300/4L IS and the 400/5.6L.

That system would be virtually the ultimate hand-holdable "reach" camera system for good light applications.