94x zoom lens patented—is a Canon SX100 planned?

 

 

Photographers looking for the ultimate in image quality might avoid zoom lenses like the plague, but the popularity of increasingly long-zoom cameras suggests that some people just can't get enough telephoto reach. If you're in their number, you may find the promise of a recent patent filing by Canon Japan to be rather thrilling.

Admittedly, most patents make for somewhat dry reading, but this one, uncovered by Japanese engineering blog Egami, suggests that Canon could soon offer a camera with close to a 100x zoom range. (Given that the existing Canon SX50 HS sports a ~50x zoom, Egami cheekily suggests the name Canon SX100 HS for a followup, tagging its image on the lens diagram with the moniker.)

But could this be a step too far? Ultrazoom cameras currently top out at 60x zoom with Panasonic's DMC-FZ70 / FZ72, and they already provide an extreme challenge to lens designers. The longer the lens gets, the tougher that challenge becomes -- which means even greater compromise in terms of image quality and lens characteristics. And that certainly seems to be the case here, with a maximum aperture that falls from f/3.5 at the 3.6mm actual wide angle to just f/9.0 at the 340mm telephoto. (35mm-equivalent focal lengths would depend on the image sensor size used, and the image circle isn't stated, so we can't yet calculate these.)

 

Optical diagram for the Canon-designed 94.4x zoom lens, from the Japanese patent filing.

That's a 94.4x zoom range, and the aperture falls quite far at telephoto despite a complex 13-element, 10-group optical formula to achieve it, including three aspheric elements (five aspheric surfaces), one fluorite element, and one ultra-low dispersion element. Hand-holding photos at the telephoto position would be challenging indeed with an f/9.0 maximum aperture and, presumably, a postage-stamp sized sensor at best.

Nor is it the most compact of lenses, with a minimum length of 3.8 inches at wide angle even before you place a sensor, electronics, and display behind it. Zoom out to the telephoto position, and it extends to over 6.5 inches, with most of the mass concentrated at the front of the lens, far from the camera body. And again, that's going to make hand-holding an even more challenging proposition, even if stabilization can be added to the design. (And that, so far, hasn't been stated.)

Of course, this is currently just a pending patent application, with the actual patent yet to be granted. The patent could, presumably, still be denied, and even if granted there's no guarantee Canon believes a 94x ultrazoom camera to be commercially viable. (Patents are as often registered to stop a rival from creating a product, or to provide legal armament against rivals and patent trolls, as they are for use in actual products -- if not more so.)

What do say you, folks -- would a Canon SX100 HS with whopping 94x zoom lens be a product you'd want in your camera bag, or has the ultrazoom game gone too far? Sound off in the comments below.

(via Photography Bay)