The core technology of SIGMA

There is a saying that “the photograph is determined by the lens”. Specializing in a variety of interchangeable lenses, this is regarded as the key device for SIGMA and their core technology. We talked to the technicians at the forefront of lens development
to discuss “the core of SIGMA”.

Text : SEIN Editorial division photo : Yuskue Nishibe

The three elements of lens development, ‘Design, Manufacturing and Inspection’.

The ever increasing pixel count of digital cameras has led to the demand of even higher image performance, to the point that not even the traditional method of using lenses to make comparisons can be used to differentiate between them. Higher performing products can be created depending on the development of new materials and techniques, but the manufacturing process has become more complex and more sophisticated to a point that there is a growing importance towards the appropriate development of high performance lenses in this age of ultra-high resolution.

It is said that requirements necessary for excellent lens making are for the highest standard of design, manufacturing and inspection to be met. For this piece, we asked 3 technicians with a wealth of experience between them about the many different points of our own manufacturing framework in SIGMA’s lens development, beginning with the upper level of development, optical design. We discussed with Tomoki Khono, a man who has handled many products, about what distinguishes SIGMA lenses from other designs.

SIGMA’s ‘optical design’ that carries the project.

“For optical lenses, every manufacturer develops their lens with the same goal in mind. The characteristics and direction of the lens would be decided by how high the bar is set, where the emphasis is placed and the extent of the balance between everything. These slight matters of adjustment can be decided by the tastes and desires of the optical engineers”.

“In general lens development, the room to maneuver may be very minute. The design of a product is held within a variety of physical constraints where it tends to strive for an overall balance and with it a high average retail price. However in SIGMA’s case, as the degree of the optical engineer’s involvement is fairly large during the preliminary discussions, it’s often the case that the product planning division only suggests the development concept and a tiny part of the basic design specifications. This may be the biggest difference between us and other manufacturers. As well as the factor of the engineer’s preferences, having a clear guide with an order of priority, such as putting performance first or focusing on a common aspect, makes work easier.” (Khono)

With one line, the harmony of what the user wants with the joy of the maker to create a “happy optical design”.

‘The joy of realizing’

As we at SIGMA only specialize in cameras and lenses, we are all passionate fans of photography and photographic equipment; hence the many young technicians who want to work on camera development or designing practical lenses. Approaching the product development from a user’s point of view can be regarded as an advantage in design.

As the technicians are designing lenses they really want to have, it is natural that their feelings behind it are strongly felt. For those on the decision making side, there are many cases where criteria is judged loosely. They are of the opinion that the challenge is worth it for the desired result and they would rather place innovation over sales. This may lead to frustrations arising from unforeseen outcomes that appear at a stage in development. There are also times when the lens hits the market and sells more than initially predicted, and the reverse is also true (laughs). But at SIGMA, the designer is not to blame. If we said that the result is tied to profits even if it’s a good idea, any person would be discouraged, right?

The fact is we believe that this kind of climate is important for the quality of design. It’s very important to approach the upper levels of lens development with the creative room for the technician to pursue what they think to be truly great with an open-minded environment, a free mindset, as well as letting them search out the possibilities. (Khono)

At SIGMA, the extent of the involvement of the engineers in the product design is significant. To realize the ideal shape by pursuing the ideal and overcoming problems along the way.

To meet with whatever design

On the other hand, according to Hiroyuki Seki, a man abundant with experience in mechanical design through working on joint projects with other companies, the involvement of many sites, such as through the process of exchange between design and manufacturing and the co-operation between SIMGA and its clients, is a characteristic of SIGMA’s approach to development.

“Though the integrated production system of our Aizu factory is no longer the identity of SIGMA, it’s not just that our engineers are among the cream-of-the-crop, but we are also committed to the development of materials, the processing of parts, and the start-up towards mass-production right up to the evaluation of the lens’ performance. Including those from on-the-ground within and outside the company, the feeling is like being locked in a tight scrum.”

“I believe this period of remarkable lens performance has brought about significantly more complicated lens production than in the past. And besides, as SIGMA is going forward with reforming its new line of lenses, the standard of quality, performance and character is increasing whichever lens you choose. The reality is that there is an increase in lenses that are very fun to use, but incredibly difficult to design. However, no matter how great the design, if the skills to give it shape are not there, it would just be a pie in the sky. So to have one’s own advanced integrated production line is the greatest weapon a manufacturer can have I believe.” (Seki)

The micro odor is a cornerstone of high process technology, an accumulation of effort to make the parts more accurate.

To develop constant discipline for production

With CEO Kazuto Yamaki likening it to an “athlete’s muscles”, the factory is undergoing training on a constant basis to keep on pushing higher. Also with the high-precision production skills at the Aizu factory, cultivated through many hours of hard work, I believe we see our fundamental thought to be against “alignment” by way of arranging the axis of lens parts.

“SIGMA has traditionally driven towards precise parts rather than alignment to improve the performance of its lenses, that is to mean consistently taking the line to ‘raise the precision of each and every part’ ever since it’s early years and thereby raising the end quality of the whole product. The performance criterion of digital has recently become stricter. With the increasing use of aspherical lenses and special glass material, the alignment that is necessary in the latter stage is still the highest level of adjustment. To pursue the precision of parts and processing without the need to do that has become part of our DNA”.

“However, with 4K and 8K high-resolution images becoming the norm, I think that small shade of difference will be the element that will determine the overall performance of a camera. This is not something that can be achieved in a very short time, but over a few decades, within the interplay of those involved every day. It’s like peeling off a thin layer one at a time to achieve this, by way of piling on the conflict between design and production (laughs). Every day, we do our best to aim for improvement, to reach a world where we can maintain a certain level for the first time” (Yamaki)

The evolving “production eco-system”

There is a world of difference between the “quantum leap” of easily marketable digital technology on the one hand, and the not so easy to reproduce analogue technology of lens production. A major aspect of SIGMA is the “scene” that has organically taken shape and is centered on our sole manufacturing base, the Aizu factory, formed among their manufacturing engineers alongside our headquarters’ development engineers and also each of our suppliers. For Masaki Yoshino, well versed in optical and mechanical design, this characteristic can be felt on the production structure, which has the involvement of those inside and outside the company.

“It is not only the Aizu factory that has grown but also our suppliers that have worked alongside SIGMA have grown together with us. Having been acquainted with these suppliers for a long time, SIGMA has a ‘very local’ source and production structure which is quite uncommon in this day and age. The intention is that, through cooperating with those involved, the standard in production that SIGMA asks for can be naturally shared and where we can together take our products to the next level.”

“Technicians in other companies have mentioned to us they are jealous we have sites that meet this high level of design. If for cost reasons this level of cooperation would have to be cut, it is presumed the accuracy, development speed and production that has been built up together would decrease. This loss would be hard to re-balance. This is why we feel there is a kind of unique ‘performance’ with SIGMA’s production system where we are all going forward together as a whole” (Yoshino)

A rare area in production that gives added value to our products, the lens is a part that is not easy to reproduce.

The right ‘calibration’ for the high-resolution age.

Before all of SIGMA’s new lenses are shipped out, they go through our very own MTF testing machine ‘A1 (Aizu 1). Success in our products can be confirmed when the abilities of the lens produced can be demonstrated for the first time, depending on the design towards high performance and high precision of the manufacturing process. The intention to develop and introduce this newest performance evaluation measurement machine is explained as follows by CEO Kazuto Yamaki, who directed the project.

“Before the development of A1, MTF measurement machines had used general sensors up to a point to measure lens performance, but after we reformed our lens production, the accuracy of those testing machines did not meet the standard we needed. For conventional machines, the resolution did not correctly measure to an appropriate standard. After analyzing a variety of results, we came to the conclusion that the wisest course of action was to develop one with our own Foveon Direct Image Sensor.”

The use of the Foveon sensor as a measuring device was a first for us and there was reasonable concern that trouble would occur. However since our technicians are well informed about the qualities of the Foveon sensor, because of our own handling of cameras at the factory, it was something we were ultimately satisfied with. We are able to test to detect high frequency elements which we were not able to do before, greatly contributing to the guarantee of quality of our new line of lenses”.

“We will of course purse the highest level of design and production as the resolution of cameras increase, but to improve the accuracy and efficiency of the final checks is also very important. Not only with testing, but our belief moreover wants to reinforce the production structure so that it supplies the quality alongside the quantity of ultra-high performance lenses.

Following the SIGMA philosophy, the headquarters, factory and suppliers work together as one to strive for higher dimensions.

Cultivated from the development in our headquarters, the factory’s manufacturing and the work of our suppliers, the know-how in our ‘scene’ has given birth to a greater level of innovation where the whole is greater than the sum of it’s parts. To work on a ‘dream team’ that can work towards realizing a higher form of creation is something we want to work is what I have in mind.” (Yamaki)

Kazuto Yamaki


Entered SIGMA in 1993. In charge of mechanical design. Has experience as a camera project leader.

Masaki Yoshino

Development Division / Mechanical Design

Entered SIGMA in 1995. Knowledgeable in optics and mechanics. In charge of many cameras and lenses.

Khono Tomoki

Development Division / Optical Design

Entered SIGMA in 1995. Mostly worked on DP Merrill and dp Quattro series etc.

Seki Hiroyuki

Development Division / Mechanical Design

Entered SIGMA in 1994. Knowledgeable in optics and mechanics. In charge of collaborating with other companies.

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