EF200-400mm f/4L IS USM Extender 1.4x is a high-performance super telephoto zoom lens with a built-in optical 1.4x extender. Not only is this lens high in image quality, with only a flick of a switch, the zoom range can be increased to 280 to 560mm. Read about behind the scenes of the development of this lens. In Part 1, we will take a look at the background and the early stage of the development.

Prologue

Birth of the ultra telephoto zoom lens

In the spring of 2013, mass production of a new lens started at Canon's Utsunomiya plant, north of Tokyo. It had been more than two years since the development of this lens, the EF-200-400mm f/4L IS USM Extender 1.4x, was announced. To explain why it took so long to create this new product, we must look back several years.

When planning for this lens began, Canon was considering developing a new zoom lens to enhance its ultra telephoto lens lineup. Surveys targeting top-tier professional photographers made it clear that demand for ultra telephoto zoom lenses was growing.

Such lenses were no longer particularly rare in the market. It looked like it should have been easy for Canon, with their cutting-edge technologies and know-how at its disposal, to develop an ultra telephoto zoom lens delivering superb image quality.

But product planning personnel at the lens division and people in charge of product development at the Optics R&D Center set a very ambitious goal: To develop a lens that would undermine the conventional notion that zoom lenses are generally inferior in optical performance to single focal length lenses.

At that time, one of the most popular lenses used among professional news and sports photographers was the EF400mm f/2.8L IS USM. Everyone on the team developing the new ultra telephoto zoom lens agreed to set a goal of creating a zoom lens that offered high image quality comparable to that of the current favorite of professionals.

News and sports photographers carry only a small number of lenses due to physical and space constraints. A 200-400mm f/4 zoom lens would be the realistic limit for a usable lens of practical size and weight. But rather than aim to develop a simple 2x zoom lens, the development team members set their sights on achieving the optical performance of single focal length lenses designed with image quality as the top priority. As a result, the team faced hurdles of greater magnitude than those they would have encountered by developing an ordinary zoom lens.

As they started flashing out ideas for the new lens, developers came up with the idea of equipping it with a built-in extender. From early on in Canon's long history of developing lenses for broadcasting, the company equipped these lenses with built-in extenders. Developers for the new ultra telephoto zoom lens thought that it might be possible to expand its usefulness and versatility by adding an extender to its 2x zoom lens optical formula.

No such lens had ever been commercialized for SLRs up until then. But professional photographers had been attaching extenders to telephoto lenses to capture the world in ways that extended beyond the capabilities of lenses alone.

The addition of a built-in extender would provide even greater convenience. Furthermore, befitting Canon's tradition of producing first-of-a-kind lenses, the creation of a lens with a built-in extender offering image quality rivaling that of single focal length lenses would add to the company's heritage of innovation and open a new chapter in the history of lenses.

These ideas drove developers to adopt the goal of creating the world's first super-high image quality lens with a built-in extender. The development project for the new ultra telephoto zoom lens thereby began.