Designing A Nikkor Lens

Lens design is a very intricate and carefully planned process. The talented lens designers behind Nikon's Nikkor optics have spoken about their design experiences and here we reveal some of their thoughts:

The advantages of interchangeable lenses

Takayuki Sensui works in the development sector and he says that there is no such thing as a perfect lens. By this, he says, he means that it's impossible to create a lens that is brilliant at taking photos in every scene or situation. "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.", he says.

Toshinori Take, another development sector worker, says that every lens has different characteristics and this is what makes using interchangeable lenses enjoyable. 

What is the thought process of a lens designer?

It all starts by thinking about a lens that you yourself would like to use, explains Takayuki. Also taken into consideration is how consumers will use the lens. Even now, in the modern digital age, lens design at the core has not changed much. 

The role of lenses hasn't changed in this time either, adds Toshinori. Light enters the lens and passes through optics to form an image. The only thing that's changed, he says, is there the image ends up - on a digital sensor instead of film. Older lenses can still be used om modern cameras with great results. 

The difficulties of lens design

"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.", explains Takayuki.

"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.", says Toshinori.