Canon cooks up constant f/4 superzooms for its APS-C cameras

Canon lens patent drawing
(Image credit: Canon Watch)

A Canon patent application submitted at the end of 2023 hints that two new superzoom APS-C lenses are on the horizon: an RF-S 20-120mm f/4 and an 18-100mm f/4, both of which will suit a wide range of genres including landscape and wildlife. In full-frame terms, these would be 32-192mm and 28.8-160mm equivalents.

There seems to be no stopping Canon when it comes to developing new RF lenses, and the arrival of two new optics for APS-C bodies will come as welcome news. As things stand there are just four official Canon RF lenses for cropped sensor Canon cameras: the RF-S 10-18mm f/4.5-6.3 IS STM, RF-S 18-45mm f/4.5-6.3 IS STM, RF-S 18-150mm f/3.5-6.3 IS STM and RF-S 55-210mm f/5-7.1 IS STM.

Although the current lenses offer a wide focal range, they all lack one major thing: constant apertures. These newly designed lenses have a fixed f/4 aperture, resulting in a shallower depth of field and better low-light capabilities – and also enable video shooters the ability to change focal lengths without the aperture shifting. 

According to the patents, both lenses will be fixed-length zooms – meaning that the physical length of the lens does not change. This is another positive for video shooters, as zooming in and out won’t affect how the lens is balanced, so there’s less chance of camera shake. 

No information regarding the minimum focusing distance, size, weight or costs of either of these lenses is available, and it may be a long time before we hear any more news. As the lenses feature an internal zoom, Canon’s engineers will have to find the perfect balance when it comes to high optical performance and the number of lens groups that move.

As will all lens patents, we may never hear anything more of these particular models if development is unsuccessful. We've seen a lot of Canon patents come to fruition, however, so 2024 could be the year that it puts more focus on its APS-C customers. 

Take a look at the best Canon cameras along with the best Canon RF lenses for mirrorless bodies and best Canon lenses for DSLRs

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Hannah Rooke
Staff Writer

Having studied Journalism and Public Relations at the University of the West of England Hannah developed a love for photography through a module on photojournalism. She specializes in Portrait, Fashion and lifestyle photography but has more recently branched out in the world of stylized product photography. For the last 3 years Hannah has worked at Wex Photo Video as a Senior Sales Assistant using her experience and knowledge of cameras to help people buy the equipment that is right for them. With 5 years experience working with studio lighting, Hannah has run many successful workshops teaching people how to use different lighting setups.