Optical Designer Interview - RF Lens World - Canon South & Southeast Asia

The zoom lens and the macro lens share a similar design. To increase the shooting magnification, the macro lens greatly extends the range of each lens, much like a zoom lens. However, autofocus needs special design because it requires speed and precision, unlike manual zooming. Because of this, autofocus-capable macro lenses are built with a lot of technology to achieve speed and accuracy. This includes handling and controlling the lens in addition to its weight and trajectory when it moves.

We set our goal for this lens at 1.4x magnification to allow for more expressive and confident macro photography. It is simple to lose focus when using a 1.0x magnification lens if the subject approaches the position even a little bit. However, there is more shooting distance available when you use a macro lens capable of up to 1.4 magnification. Even if the subject moves suddenly closer, it will remain in focus, allowing you to snap confident photos. Moreover, when captured at a magnification of equal or greater, it can portray a stunning world that is entirely distinct from what your eyes perceive. With this lens, I want you to be able to see the stunning macro world.

To achieve a 1.4x magnification this time, it was necessary to deviate from conventional types. Maximising the range of motion of the focus lens became possible due to the large aperture and short back focus. Unlike conventional macro lenses, this lens achieves 1.4x magnification by moving the focus lens to the very edge of the mount, separating the focus from the IS, and placing the aperture in front. Over time, the optics of a typical macro lens have been improved, yet its focus type, IS type, and aperture position remain largely fixed.

It's crucial to avoid getting stuck in traditional thinking and to always begin from the basics. I think it will be difficult to break from the usual and innovate in any field. The design of this macro lens started with a single convex lens, rather than being based on existing lens designs. As a result, this lens may have a completely different configuration compared to other macro lenses when you look at their cross sections.

Special lenses are typically used to reduce aberrations, but this lens accomplishes this without the need for special lenses. This is achieved by incorporating a concave lens in the foreground to gently receive light rays from close subjects and gradually bend the light, reducing spherical aberration. Additionally, a convex lens is added to correct chromatic aberration.

When you increase the magnification for shooting, the focus range becomes very narrow, and the blurred range increases, allowing for more mystical depictions. However, even a small camera shake can make the camera go out of focus, which makes it hard to focus on the area you want to capture. Also, because the subject appears larger, camera shake has a bigger impact than usual. So, when shooting at 1.4x magnification, you need precise autofocus and strong image stabilisation.

When the image stabilisation lens is engaged, we intended the aberration variation to be less noticeable. For even more effective image stabilisation, it also works in together with the camera's in-body image stabilisation system.

We needed to move several lenses further to obtain 1.4x magnification. The "Nano USM," a Canon’s proprietary ultrasonic motor, powers this lens's high-speed, high-precision autofocus.

We designed this lens to produce high-quality images in all shooting situations, including landscapes and portraits. It is not just suitable for macro photography.

This macro lens is equipped with Nano USM, allowing for comfortable video shooting with quiet and quick autofocus. Additionally, when shooting video, you might be concerned about focus breathing, which is the change in angle of view during focusing. With the adoption of a new focus type for this lens, focus breathing is mitigated.

The Nano USM's ability to freely alter the focus trajectory served as a foundation for the concept of controlling the spherical aberration, or "SA." We could enhance the freedom of expression by softening or hardening the bokeh by carefully adjusting the aberration, which only served to degrade the quality of the image.

I've been photographing killifish and tiny shrimp. Ever since my child got a killifish, I've set up an aquarium at home. Setting up the aquarium has been enjoyable for us, and now we have four of them. It's great to see the small fish and prawns swimming around, and I can now easily take close-up shots of these fishes handheld. The lens focuses quickly, has minimal shaking, and the 1.4x magnification offers a unique perspective. With this lens, I hope you enjoy macro photography as much as I do.