Technology & Philosophy

vol.2

What do designers think, and how do they create lenses?

The advantages of interchangeable lenses

Development SectorTakayuki Sensui

The first thing I can say is that there is no such thing as a perfect lens. By this, I mean that it is impossible to create a lens that is perfect for capturing every type of scene or subject, or for use under all possible conditions. For example, fixed focal length (prime) lenses offer expression and characteristics that are unique to that type of lens. Zoom lenses, on the other hand, are developed with the pursuit of convenience. This makes achieving unique photographic characteristics difficult with this type of lens.

Takayuki Sensui

Development Sector
Imaging Business Unit, Nikon Corporation

Takayuki Sensui first encountered the Nikon F in his third year of middle school through the influence of his father and continued using it all through high school and college. While in college he worked part-time at three major camera specialty chains, and memorized the catalogs of every manufacturer front to back. After graduating, Takayuki gained experience designing everything from auto focus to exchangeable lenses and viewfinders while working at another company before finally arriving at Nikon in 2001. He chose Nikon out of a desire to be involved in the professional field of high-speed user-focused R&D. Despite being told at the time of his transfer that he would be a designer for the rest of his career, Takayuki became a manager during his sixth year, with the reason for his promotion apparently being “the ability to see Nikon objectively due to having worked for other companies.” Declaring that lens design is an artform, Takayuki is a lover of refined jazz who plays the drums every weekend.

Development SectorToshinori Take

Every lens has its own unique characteristics such as soft or hard rendering. That is what makes using interchangeable lenses so enjoyable. By using interchangeable lenses, a single camera can be transformed into various types of cameras.

Toshinori Take

Development Sector
Imaging Business Unit, Nikon Corporation

Everything started with Toshinori Take’s love of photography. He spent so many days in the dark room in high school that he earned a reputation for smelling of liquid developer, and eventually enrolled in a university specializing in optics. When it came time for Toshinori to consider what sort of photo-related profession he wanted for himself, he joined Nikon in hopes that he would be able to help photographers by making camera equipment. He was involved in lens design from the beginning, and was in charge of many optics systems for film compacts, single-lens reflex finders, COOLPIX, and 1 NIKKOR. Toshinori now oversees all F-mount interchangeable lenses. He is known as a researcher-type who tries all sorts of lenses (including those from other brands) own his shoots and the provides R&D feedback.

Development SectorTakayuki Sensui

Interchangeable lenses enable varied views and expression of the world around us using a single camera.
I believe that interchangeable lenses can be positively enjoyed not only with our D-series cameras, but also with non-reflex cameras, as they are known throughout the industry and more commonly as "mirrorless" cameras, such as our Nikon 1 cameras.

AF-S NIKKOR 28-300mm f/3.5-5.6G ED VR

AF-S NIKKOR 28-300mm f/3.5-5.6G ED VR

Which lenses would you choose?

Development SectorToshinori Take

My first choice of lens would be the 400mm f/2.8 (AF-S NIKKOR 400mm f/2.8E FL ED VR). I often take pictures of moving objects such as trains, automobiles, and airplanes. With excellent mobility in a lighter package and a SPORT VR mode that stabilizes the viewfinder image, this lens is ideal for this sort of photography.

AF-S NIKKOR 400mm f/2.8E FL ED VR

AF-S NIKKOR 400mm f/2.8E FL ED VR

Development SectorTakayuki Sensui

Though in doing so I am blowing my own horn a little, I would choose the DX 35mm f/1.8 (AF-S DX NIKKOR 35mm f/1.8G). While the fact that I designed this lens myself makes it attractive to me, it is also an inexpensive lens, priced in the ¥30,000* range, that offers quite good performance. While many people start with zoom lenses, I think that this single 35mm fixed focal length lens is a great introduction to the world of interchangeable lenses.
*As of December 15, 2014 (manufacturer's suggested retail price)

AF-S DX NIKKOR 35mm f/1.8G

AF-S DX NIKKOR 35mm f/1.8G

What do designers think?

Development SectorTakayuki Sensui

Whether designing an expensive lens or an inexpensive one, optical designers begin with consideration of a final product that they themselves would use, or more precisely, how customers would use it. Basically, we consider the fact that lenses compress the three-dimensional world into two dimensions. In fact, only lenses can compress three dimensions into two. This is also the nature of the optical devices we know as cameras. Seen from this point of view, the nature of lens design has not changed for decades.
Even with the transition to the digital age, the basics of lens design have not changed. Portions that cannot be compressed are blurred and out of focus when rendered to a 2-dimensional plane.

Development SectorToshinori Take

The role of lenses has not changed. The light from a subject enters the lens and passes through the optics to form an image. The only thing that has changed is where the image is formed—on film or on a sensor.
Therefore, if users like the characteristics of older lenses, they can thoroughly enjoy using them with the latest digital cameras as well.

The difficulty of lens design

Development SectorTakayuki Sensui

One of the most difficult aspects of lens design is the fact that for every stop (f/number) lens speed increases, aberration that degrades the image increases by the third power. If, for example, lens speed is increased from f/4 to f/2, it makes optically correcting for aberration eight times more difficult. As the cost of the lens cannot be eight times higher, designers must always be considering ways to design such lenses with as little increase in cost and weight as possible.

Development SectorToshinori Take

While designers are not allowed to become complacent or smug, they are allowed to pursue a level of performance and a preferred level of aberration based on the needs of potential users of a particular lens.
An individual designer may spend as long as several years working on a single lens until it is finally complete. While this can be extremely difficult and trying, there is little that makes designers happier than seeing their lens completed and used by photographers.