Canon May Be Cooking Up Some Wild RF Zoom Lenses

Canon may be working on some seriously ambitious RF lenses, if its latest patent filings are anything to go by.

A new report from Canon Rumors details three full frame zoom designs, including an RF 70 135mm f/2L IS, an RF 200 400mm f/4L IS, and an especially interesting RF 180 600mm f/6.3L IS. None of these lenses is confirmed for production, but the designs offer a glimpse at what Canon’s engineers are exploring.

The report is part of a recent run of Canon lens patents covering some unconventional RF designs. This latest application focuses partly on making large zoom lenses faster and easier to operate.

Canon is looking at faster zooming

According to Canon Rumors, the patent describes a zoom system using three independently moving groups in most of the lens designs. The front optical group remains stationary, which could reduce the amount of weight that has to move during zooming.

That could make a difference with lenses containing large amounts of glass. Moving lighter internal groups instead of the largest front group could potentially make zooming quicker and require less force.

The RF 70 135mm f/2L design appears to use a different arrangement, and the report notes that it is not clear how its zoom groups are configured.

The designs also use internal zooming, so the physical length of the lens would not change as the photographer moves through the focal range. That can be useful for maintaining balance and for applications where the lens needs to stay relatively sealed.

All three designs have a 21.64mm image height, indicating that they are designed for full frame coverage without relying on extreme computational correction.

The 180 600mm could be the wild card

Of the three designs, the proposed RF 180 600mm f/6.3L IS stands out.

Canon already has the RF 100 500mm f/4.5 7.1L IS USM, but a 180 600mm lens would offer considerably more reach while maintaining a constant f/6.3 aperture across the zoom range.

The concept would also put Canon in an interesting position against Sony and Nikon, which already offer 600mm f/6.3 lenses. Those competitors use fixed focal lengths, while Canon’s proposed design would add the flexibility of a zoom.

The tradeoff would be size and weight. A full frame 180 600mm f/6.3L zoom with internal zooming would need to pack a lot of optical hardware into a relatively ambitious package.

Canon Rumors also points out that the designs appear to use a single moving focus group rather than the dual focus groups seen in some of Canon’s recent patent applications. That could indicate a conventional USM focusing system rather than a setup using multiple voice coil motors.

Canon is not alone in the patent game

Lens patents are common across the camera industry, and they should not be treated as product announcements. Manufacturers regularly explore optical designs that never reach production.

Canon has nevertheless been unusually active with interesting RF lens patents recently, including designs for lenses with different combinations of focal lengths and apertures.

Other manufacturers are doing the same. Sony, Nikon, Panasonic, and other camera companies routinely file patents covering new optical configurations, autofocus systems, and lens mechanisms. Patent filings can therefore provide clues about the engineering problems manufacturers are investigating, but they cannot tell us which designs will eventually become products.

That distinction matters here. Canon could ultimately release a lens based on one of these designs, change the specifications substantially, or abandon the concept altogether.

Two f/2 zooms are hard to ignore

The most intriguing part of the filing may not actually be the supertelephoto.

Canon is also exploring an RF 70 135mm f/2L IS, alongside the previously reported RF 20 60mm f/2L VCM design. Two constant f/2 full frame zoom concepts would give Canon an unusually fast zoom lineup if even one makes it into production.

For now, these are optical designs on paper rather than lenses you can put in your camera bag. But if Canon really does have more RF lens announcements planned before the end of 2026, photographers will have plenty of reason to keep an eye on those patents.

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