3D lenses and cameras sound intriguing, but how relevant are they to consumer photography?

Looking into the patents registered by camera manufacturers can be a double-edged sword. On one side, you have the excitement and hope of an upcoming product release. On the other, complete confusion over why a company would file a patent for something which isn’t in demand. Patents also aren’t a strong indicator of release dates and more often than not, a patent remains in limbo forever. Canon’s latest patent for a 3D lens system has me a little confused

3D stereoscopic film cameras have been around for decades. There have also been a few digital ones like Fuji’s Finepix W1 and Panasonic’s Lumix DMC-3D1, but possibly none yet with a Full-Frame sensor. Nikon has had 3D patents in the past, but those were to create 3D images from a single 2D image. Canon might be hoping to pioneer 3D Full-Frame imaging with the registration of this patent, filed some weeks ago

What Does the Patent Say?

The patent for a 3D lens for Canon was first spotted by the folks at Hi Lows Note. Patent application P2021-51282A (Japan) details the requirement of a design for a “stereoscopic lens device capable of obtaining a natural three-dimensional effect by appropriately setting a baseline length” (translated from the original Japanese). What’s interestingly though is the lens design, with each lens appearing to house two mirrors. The internal mirrors appear to be added to produce both image circles inside one Full-Frame sensor. And there is sufficient distance between the two front elements to provide a proper stereoscopic 3D effect.

L1 in the diagram below is the distance between the two optical axes of the first lens element, while L2 is the distance between the two axes of the innermost lens elements.

As the patent states, “The average distance between the human eyes is about 60 to 65 mm, and in order to obtain a more natural three-dimensional effect similar to that of the human eye, it is necessary to use an optical system having the same baseline length. However, to realize this, it is necessary to make the aperture of the lens mount larger than 60 mm, so that the lens device and the image pickup device become large” (translated).

The patent notes also state that this system is designed to work on a 24x36mm sensor. Section 0031 further says that the focus ring (205) can be configured to adjust focus, aperture, or zoom. Canon’s DSLR system of lenses does not have such a configurable option. Thus it would indicate that this 3D patent is designed for their current mirrorless RF Full-Frame mount. Keeping the lens compatible with existing bodies is a good idea, maximizing the sensor area for the image circles being projected onto it. Add AI into the equation somewhere, and it might be a unique product that everyone takes notice of in the future.

Do We Really Need a 3D Lens and Camera System Outside of Hollywood?

My personal experiences with 3D haven’t been too memorable. Testing the stereoscopic Nintendo Virtual Boy as a teen at a gaming fair in 1996 gave me a disorienting headache. The last 3D movie I saw was the nearly two hour-long ‘The Adventures of Tintin’. I remember walking out of the cinema wishing I’d just gone for the 2D version instead. It wasn’t just that I didn’t find the format interesting (how often can you be amused by things on-screen flying directly at you). I couldn’t fathom why others would bother putting their eyes through such a strenuous experience for hours. 3D TV sets haven’t been very different. I still maintain that 3D TVs wouldn’t have made it into people’s homes over the past decade if not for James Cameron’s idea to film Avatar in this format. Most mainstream TV manufacturers have discontinued the production of such units, which makes you wonder if there really is a future for consumer 3D technology.

My personal feelings on 3D tech aside, you don’t hear of big-name photographers talking about it or of consumer camera brands saying ...