Canon USA has published an interview with the developers of the brand new Canon EF 400mm f/2.8L IS III and Canon EF 600mm f/4L IS III super telephoto lenses, the lightest lenses of their kind in the world.
A lot more went on during the development than just weight reduction. New challenges lead to new materials, manufacturing processes and functionality.
Some of the design goals and challenges facing the developers:
- Rather than simply making the lens lighter, we retooled the lens from the ground up for an overall balanced weight.
- Improved mobility and portability, with reduced weight
- A significant — not average — reduction in weight
- We were convinced we could reach our goal thanks to the
proposal of a new optical system.
- New challenges, one after the other, with tag-team efforts
between Optical Design, Mechanical Design, Electrical
Design, and Production that overcame these challenges.
- Reducing the number of component s results in both
a lightweight design and increased strength.
- Using a new high-strength alloy for the lens barrel
- Using the latest gyro sensor is insufficient for improved
IS performance — it was necessary to build a new control algorithm that assumes a variety of situations.
- Not only has handheld IS performance improved, but it can
now deal with vibration when using a tripod.
- Improved lens focus drive speed even when an EF tele-extender is attached.
- An expert coating team was formed with the cooperation of the
Mechanical and Manufacturing departments within Canon, to aim
for an ideal solution.
- We didn’t compromise on the white color, despite placing
priority on functionality.
The Full Canon Developers Interview (19.6mb PDF)