Carl Zeiss AG
Executive Vice President
Consumer Optics Business Group
Dr. Winfried Scherle
Dr. Scherle joined Carl Zeiss upon graduation from university. He has continued to work with the company for the past 30 years and is now the head of the Camera Lens Division. We interviewed him about lens R&D, his views on 4K and 8K, and the current state of Carl Zeiss.
What are the most important criteria in the production of a Carl Zeiss lens?
Compact Prime Lenses
Master Anamorphic Lenses
Ultra Prime Lenses
In terms of technology, it is important to listen to our customers, so we like to talk with the photographers who work with us. Our focus is on how our customers are using our products. For example, we began by making small lenses, but we started producing larger lenses for use with motion picture cameras. In other words, it’s about application. It’s about how our customers want to use our products. We have so many lenses, and it is really up to the customers how they use them.
For example, we manufacture Batis lenses which have an autofocus function, but we also make manual lenses for cinematography. What I would like to clarify here is that we don’t want artists to rely on our equipment to create something new, but rather we want them to view our equipment as responding to the artist’s desire to create.
If you take a look at the Master Anamorphic Lens, technologically speaking it is obvious that it’s a high-end lens. I don’t think anyone else is capable of achieving that level of quality.
What has changed the most in terms of R&D in the transition from film to digital era?
In this digital age, you can look at large images and see great details. The overall optical system has made significant progress. This is one factor. Another is that there are more “opportunities” — whether it’s in still photography or moving pictures. For example, in the past if you wanted to take a picture, you had to hire a model and work to capture that decisive moment, but now things are much simpler. You can run the video camera and then select the best image later. It’s easier than ever for people to record images, and this has benefitted customers who use ZEISS products as well. We are also putting our energy into making our high-end products easier to use. Our motivation is to create high-performance products without sacrificing image quality. That’s our core motivation.
The big challenge when it comes to 4K and 8K resolution is the harmony between image clarity and achieving an artistic look. What are the challenges you face in manufacturing the lenses?
Many people are talking about 2K, 4K and even 8K, but my personal opinion is that this is not the right approach. Carl Zeiss lenses are 8K-compatible, but then we are simply offering quality and not talking about 8K itself. It’s important to take a look at contrast. This is because you don’t necessarily place moving images under a microscope and count pixels in an image. The question is about the image quality that a lens is capable of offering. While I have seen 8K cameras with a Compact Prime Lens provide an image with great resolution, the 8K is a matter of marketing. If your TV has a 2K resolution, you might consider it to be a very good experience. The 4K might be even better, but it doesn’t necessarily follow that this will be the case for the 8K. I can’t say that it is good for the customer. You would need to sit farther than normal from the TV screen, and everything that went into producing the image would have to work with the 8K. You need to verify the contrast, low-frequency, flare suppression, high dynamic range, etc.
This is a never ending discussion among lens aficionados, but what is a beautiful bokeh?
To achieve beautiful bokeh, you have to have optical and mechanical harmony. Generally speaking, a wider aperture will result in a soft bokeh, but how the focus spike appears when focusing will also be a factor of bokeh. Of course the focal length you choose will also be a key factor, but the operation, the image format, and the aperture settings are very important as well. These things all affect bokeh.
Aside from your lens specifications, why are Carl Zeiss lenses are so popular?
One reason why many people rate our lenses so highly is not only the optical performance but also the robust housing we use for our optical equipment. For example, look at our Compact Prime and SLR lenses. The lenses in part employ the same optical system. On the SLR lenses you can make distance adjustments manually while you are looking through a viewfinder, but with cinema lenses people work by measuring the distance and applying it to the scale readings. If you look at most people’s work, they say the ones producing the best results are able to do so because of the optical system, but that is just one factor. Housing is what protects this environment, and this is one reason why ZEISS lenses are so popular among many artists.
What is the Carl Zeiss motto or slogan?
It is important, of course, to continue developing our products and to evolve along with the industry. For example, we are today developing the most advanced optical process technology in our semiconductor manufacturing division. In the beginning, we were producing photography lenses, very simple projection lenses. But as the needs and specifications of the market grew, so too did the need for new technology. And that continues even today, so at Carl Zeiss we are always trying to develop new methods. Though we might make some mistakes, it is because we are constantly striving to be a game changer in the market. Now we make optical devices for computers and smart phones, offering products for the entire industry.