Canon filed a patent covering 21 optical designs for new lenses. Each one uses a 3-group construction the company says will focus faster.
Compact optical system
The Japanese patent, number 2026-122508, was first spotted by Canon Rumors. Its stated goal is a compact optical system capable of high-speed focusing. All 21 designs land in wide-angle territory, with focal lengths running from 12.2mm to 20.5mm.
Three-group lens
Three groups do the work here. The front group Lf (L1) carries negative refractive power, as does the intermediate group Lm (L2) behind it. Positive refractive power sits in the rear group Lr (L3).
Focus happens in the middle. At infinity, Lm (L2) parks close to the rear group. Pulling focus toward a near subject slides it forward toward the front.
Faster autofocus
Lm (L2) is the lightweight of the bunch, with only a few elements to move. Less mass means less power draw from the focus motor, plus quieter operation. The travel distance between infinity and close focus is short too. Both factors point to snappier autofocus in any lens built this way.
What we think
This is a concept patent, not a roadmap for a specific RF lens. Canon could apply the 3-group design across camcorders, security cameras or broadcast systems. An actual RF-mount product would almost certainly get its own filing.
Still, the focal range is telling. Nothing here goes past 20.5mm, so Canon is clearly working the wide end. Ultra-wide primes have a reputation for being heavy and slow to focus, partly because so much glass has to move. Shrinking the moving element down to a small middle group would solve that. For gimbal operators and run-and-gun shooters who fight lens weight, that’s the payoff worth watching. Most patents never turn into products, so hold the expectations loosely.
