BEHIND THE DESIGN OF THE NEW PRIMO 70s WITH DAN SASAKI

Panavision recently introduced a new line of Primo 70 lenses optimized to work with today’s larger sensor digital cameras. In the following Q&A, Dan Sasaki, Panavision’s VP of Optical Engineering, talks about the thought processes and technological breakthroughs that led to the Primo 70 lenses.

What was the thought process behind the design of the Primo 70 lenses?

We see the movement towards large sensors as the next logical step in cinematography, and that’s why we designed the Primo 70 lenses. We saw the need for lenses that are purposefully designed to work with these larger sensors, to cover the larger diagonal with consistency from edge to edge. We also wanted to bring that organic Primo quality that filmmakers love to large sensor digital cameras.

The Primo 70 lenses grew out of an extensive iterative process, a collaborative effort between the design team and our technical staff, with input from trusted directors of photography. I’d love to say we knew ahead of time how to accomplish the goals. We knew how the lenses should look. We knew that the lenses should have a strong family resemblance to the original Primos, which filmmakers depend on. But we weren’t sure how to get there. And there wasn’t a one-size-fits-all solution.

There are three basic forms – wide, medium and long – and there were three learning curves for how best to achieve the goals. It’s an empirical process, but there is also an art to it. It requires a subjective eye and taste, as well as all the measurables. Computers have made lens design much easier. But you still need to design a lens that delivers the aesthetics, is practical to manufacture, and easy to use on the set. It really is science meeting artistry.

You say that larger sensors are the next logical step for cinematography. Why?

As cinematographers migrate to larger sensors, they need to use a longer focal length to get the same field of view. What this does is create a psychological feeling that is closer to how we perceive things. This is part of the beauty of large format cinematography, a concept realized by photographers for ages. Because you are using a longer lens, your compression, your depth of field, and your perspective magnification is more natural. It actually draws you in. Your mind is not questioning, because what you see is closer to how things really look. The distances between objects can be exaggerated when wide angle lenses are used on smaller sensors. An iPhone is an extreme example of this. It doesn’t look right. But at 70mm, things begin to fall together. There’s almost a merger with your brain. Everything looks more natural. Magnification looks proportionate. When you look at a large-format photograph, it looks more or less how your eyes see. You’re not mentally having to adjust. You are not fighting magnification. The image doesn’t need to be blown up as much, so there’s less degradation of the image. You have more detail. The trees in the deep background are not pixelated or blurry. These psychological cues are important. The Primo 70 lenses combine everything we’ve learned about lenses and cinematography with the tremendous potential of large sensor digital photography.

Did you incorporate input from directors of photography?

Yes. We invited cinematographers to a roundtable discussion with our technicians. We asked them very precise questions. For example, ‘What is it that you like about newer lenses? What did you like about our old lenses? What would you like to see in a new lens?’ Oddly enough, the answers always seemed to be contradictory. Cinematographers want a lens that is sharp, but at the same time, they don’t want it too sharp. We were a little bit perplexed at first. The first rule of design is that it’s one or the other – sharp or soft. But we kept pushing our engineers, and they came up with a unique way of breaking the lens down that maintains sharpness on par with modern day lenses, but at the same time, doesn’t give you the feeling that you are looking at a lens that is synthetic or flat. Rather than making a lens that looks like a lithographic lens that produces very flat images, we preserved a lot of the three-dimensionality in the optics design that was part of the original Primo idea from back in the 1990s. It wasn’t easy.

What are the optical specifications that led to these organic Primo characteristics?

There are many facets. Without getting too complicated, we maintained a couple of directives in our design. The larger and higher-resolving sensors meant that we have to revamp the original Primo design. We needed to cover a larger diagonal while delivering top image quality that could negotiate with the digital sensor – meaning the low pass filter, the IR, and whatever glass package is associated with that. All those elements affect the light. Also, we were very careful about how the lenses look in and out of focus, and in the transition. With our first swing at it, we tried making lenses that met these criteria while giving us super sharp images. The problem we found in some of the evaluations was that the lenses went soft almost instantaneously, and gave us an unflattering bokeh that was a little on the flat side. So we made some adjustments that maintain the high MTF on the low spatial frequencies. Now, on the Primo 70s, when things go out of focus, they maintain a more interesting transitional quality, more akin to an impressionistic painting. You have a very clean image when you are in focus, but as you go out of focus, it’s not de-focused instantaneously. Instead, there’s a nice, pleasing roll off. The image decomposes or degrades in a way that gives the illusion of depth to objects, as opposed to a flat, lifeless and clinical entity. It’s similar to how we perceive depth with our eyes. The result is a very high-quality look with a very friendly, human touch to it.

Are there other differences between the original Primos and the new Primo 70 lenses?

Because digital sensors are very responsive to reflections, one of the biggest challenges was making sure all the surfaces are complimentary, without unwanted flares or glares. Also, these new lenses have full floating elements, whereas the original Primos use a fixed design. The floating design helps control breathing and maintains close focus compatibility throughout a full range of object distances. The Primo 70s maintain high performance from infinity all the way to close focus, which is something very important these days, especially with the mobility of cameras and shots.

How about ergonomics? Are the Primo 70 lenses bigger and heavier?

No. Because of the importance of mobility, one of our first requirements was that the Primo 70 lenses maintain a form factor very close to the existing Primos, and a similar weight. We didn’t want to make something that was unfamiliar. And even though these new lenses often have many more elements and much more complex movements, they are actually lighter than original Primos at similar focal lengths. We wanted to maintain a very clean-looking, universal and purpose-built set of lenses. To accomplish that, we had to take very aggressive steps and use lenses with tight radii.  We used multiple aspheric elements as well as exotic glass types to control the aberrations.  Some of these types of exotic glass were not available in the 1990s when we designed the original Primos.

Have the Primo 70 lenses been tested in the field?

The Primo 70 lenses have been used on two feature films. The first, a 2016 release shot by Peter Menzies. Jr., ACS, and the other is Ride Along 2, shot by Mitch Amundsen. They were both done on RED Dragon cameras using the full extended sensor, resulting in a 2.40:1 aspect ratio. That sensor has a 34mm diagonal, compared to the traditional 28mm diagonal normally associated with Super 35-size photography. The feedback was quite positive. Peter and Mitch were both pleased by the fact that we didn’t create a lens that was synthetic or scientifically too sharp. We maintained the artistry of the lenses, and a family resemblance to the Primos, while giving them all the resolution they would ever need.

Can the Primo 70s be used with film cameras?

No. The Primo 70 lenses are purpose built to work with digital cameras. You can’t use them on film cameras because they would interfere with viewing system mechanics, for instance. They are designed with the anticipation that there will be some optical interaction with a low pass filter and other filters such as an IR filter. It’s not an afterthought; it was actually one of the primary design specifications of these new lenses.

How do you anticipate cinematographers using the Primo 70 lenses?

For example, Menzies wanted an epic look for his film. He tested many different cameras. He loved the RED Dragon and the fact that it had a much larger sensor. The Red Dragon has a 34.6mm diagonal imager, which is quite a bit larger than an F55 or an Alexa. What really intrigued Peter was all that extra image area meant more available resolution. He tried our original Primos and a host of other lenses that were not designed for the larger sensor, all of which weren’t designed to cover the larger sensor. He was noticing fall-off on the edges, and in some cases, the lenses weren’t performing as well on the digital sensor because of the interaction of low pass filter. So we made a mount that would adapt the Primo 70 lenses to the camera. Since these lenses were designed to cover the large diagonal, with very even performance across the field, working with the RED Dragon sensor size was no problem. Peter knew right off the bat that he had the right lenses. He was getting perfect resolution from the center of the frame to the edge, which is very important.

Then, he started digging into the quality of the lens, pushing them and evaluating how they look artistically. When he saw that he could basically shoot these lenses into a direct source of light without glaring out, that was another big selling point. He also liked the bokeh, the way things looked when out of focus. He was elated.

Amundsen had a similar experience. He saw the benefits – incredible sharpness, and the ability to pull tremendous detail out of the full chip. At the same time, it’s not looking flat or synthetic. Beautiful roll-off. No need to break the image down using some artificial means. Cinematographers come to the Primo 70s because they are looking for lenses that work with the larger sensors. Then they discover the artistic aspects. We’re very excited to see what cinematographers do with these new tools.