- Introducing a composite optical element that bonds glass with resin - Significantly reduces weight and production costs, fueling anticipation for a budget-friendly f/1.2 lineup
Canon has filed a patent for an innovative lens design that could simultaneously lower both the weight and price barrier of high-performance, fast-aperture lenses.
According to a recent patent application published by the Japan Patent Office (JPO), Canon is developing a composite lens element design. The design functions as a "sandwich," where a central glass element is bonded on each side by two thinner resin (plastic) elements.
While the mention of "plastic" often causes concern among photography purists regarding potential image degradation, Canon claims this composite design offers several distinct advantages. Because plastic weighs significantly less than glass, it contributes greatly to overall lens weight reduction. Furthermore, when correcting distortion, using aspherical resin elements can deliver the same optical results with fewer elements, eliminating the need to grind down complex aspherical glass shapes.
Canon has also addressed the traditional vulnerability of plastic: its tendency to warp under extreme heat or cold. By securely bonding the resin elements to the central glass element, the design prevents the resin from changing shape due to temperature fluctuations. Ultimately, this allows the lens to reap the full optical benefits of aspherical surfaces without the expensive glass-milling process, opening the door to dramatically lower production costs.
The most eye-catching detail in the patent document is the inclusion of three distinct optical designs for an "RF 85mm f/1.2" lens. All three configurations share identical front-group crown glass and resin formulas, only slightly varying the properties of the central composite glass to optimize aberration correction and total lens length.
Industry observers speculate that following the recent release of the RF 45mm f/1.2 STM, Canon may leverage this "sandwich" patent to introduce an affordable 85mm f/1.2 STM lens to the consumer market. Currently, these PMo (Plastic Molded Aspherical) elements are rarely used in Canon's top-tier luxury 'L-series' lenses. However, they are actively adopted in popular budget primes known for their exceptional sharpness and value, such as the RF 28mm f/2.8 STM and the RF 50mm f/1.8.
Among the various prime and zoom lens designs featured in the patent, the RF 85mm appears to be the most viable candidate for commercialization. As this patent indicates that Canon will continue to accelerate its research and implementation of PMo elements, users can look forward to experiencing legendary f/1.2 background blur at a much lighter weight and a far more accessible price point.
📝 Editor's Note
"This is wonderful news for photographers who love the dreamiest bokeh of an f/1.2 aperture but have hesitated due to back-breaking weight and bank-breaking price tags. It is classic Canon engineering to overcome plastic’s thermal expansion weakness by sandwiching it with glass. We eagerly await the arrival of a budget-friendly, silver-ringed RF 85mm f/1.2 STM."
🏷️ Tags
#Canon #RFLens #LensPatent #RF85mm #SandwichLens #PMo #AffordableLens #CameraRumors