[photo] A film crew shooting a woman standing at an open door

Case Study

Why XK Series is Believed as “The Perfect Zoom Lens”


XK series which recently joined the line-up of FUJINON 4K CINELENS is the product that delivers the same level of quality images as ZK and HK series do while it also has the outstanding mobility and operability. Tokyo video production group Marimo Records carried out a thorough hands-on investigation.


Product Introduction Video

Promo Video

Promo Video - Making-

In digital cinema, it’s the lens that determines how the shoot will turn out

[photo] A fully rigged Sony digital with Fujinon XK Series lens
[photo] A front sideview of a Fujinon XK Series lens with the etched logo in focus

XK Lens—the perfect PL-mount zoom lens. Up to now, there has never been a single lens like this that offers everything in terms of image quality, mobility, and operability.

These days, video productions are increasingly being shot exclusively with digital cinema cameras built around large-format image sensors. Just a decade ago, there was a vast gulf in quality between digital video and traditional cinema technology. But since then, video equipment has made huge strides. Today, it’s safe to say we’ve reached the point where almost anyone can create cinema-quality images with bokeh or a blurred, out-of-focus aesthetic. An increasing number of companies offer new camera models with high-resolution 4K specs that enable anyone to shoot video with a level of quality that would have been inconceivable in the old days.

What this means is that the quality of the lens you use is now more important than ever. In the era of digital cinema, the lens is the only component that still conveys analog information. So when I do my shoots, I pay the utmost attention to the lens. There are sound reasons why people often choose to shoot with a single-focus prime lens. It’s generally accepted that prime lenses deliver a degree of sharpness that can’t be reproduced with zoom lenses. Of course, on location you’ll often see zoom lenses being used, too. But if I’m shooting a 4K production, say, the thought is always in the back of my mind that, if I want to shoot with a total commitment to quality, I should use a prime lens. Also, unfortunately, when it comes to PL-mount zoom lenses, there are simply fewer options available. That’s why I usually end up using a set of several single-focus prime lenses.

The debut of the XK Lens—the perfect PL-mount zoom lens

[photo] A film crew shooting a woman standing at an open door

I created a promo video for the lens, shooting at 4K resolution.

When I got the chance to shoot with an XK Lens, it completely flipped my conventional thinking upside down. This is just my personal take, but I really believe the XK Lens is the ultimate PL-mount zoom lens. It gives you all the advantages of conventional PL lenses, but at the same time it’s a zoom lens with outstanding mobility and operability. All in all, it’s pretty much perfect. By the way, we did a three-day shoot to produce a promo video for the XK Lens, using a model as the subject.

[photo] A lady in a dress standing on the beach
[photo] A medium shot of a lady dressed in a mediaval outfit standing infront of a gray wall
[photo] A wide shot of a lady dressed in a mediaval outfit sitting on a green grass on a cloudy day

Still frames grabbed from a video I shot using the XK Lens. In terms of visual rendering capability, it performs as well as a single-focus PL lens.

From 20 mm to 120 mm—shooting with a single unit

[photo] A wide shot of a lady walking on the beach

20 mm video. I was able to shoot video even up to this wide angle.

First and foremost, the standout feature of this lens is its zoom focal length of 20 mm to 120 mm. It’s fair to say that this focal length range covers virtually all of the angles of view you’ll need in video production. Even though it’s an authentic PL-mount lens, you don’t have to swap out the lenses when you’re changing shots. When you’re shooting on location, it’s all about efficiency—being able to shoot lots of clips in a short time. Swapping out lenses—and then having to calibrate color rendering accordingly—is time-consuming and painstaking work. It’s a huge plus being able to finish all your shooting with a single lens. On this job, I was able to capture nearly all of the compositions I needed using this single unit—everything from full-length shots of the model, including some fairly long shots, to full-face close-up shots.

[photo] A very close-up view of a lady eyes, nose and lips

120 mm video. At the shortest focal length of 110 cm, I was able to capture quite short close-up shots.

The real power of T3.5

Conventionally, the T-numbers go down as the zoom range of a lens gets wider. But with the XK Lens, I can shoot with a consistent T3.5 aperture value throughout the 20 to 120 mm zoom range. This came as a real surprise. What’s more, the brightness that comes with a T3.5 value was also very helpful at our production locations. When it came to making uncompromising exposure adjustments,we had no issues at all. We were able to get stable, consistent color throughout the finished work, which is another benefit of using a single lens.

[photo] A wide shot of a lady dressed in a mediaval dress & hat standing on a green grass field on a cloudy day
[photo] A face close-up of a lady dressed in a mediaval dress & hat sitting on a green grass on a cloudy day

Angles of view at 20 mm and 120 mm settings. Zooming without having to reduce aperture values.

Absolutely beautiful rendering power—no problem even at 4K resolution

[photo] A medium view of a lady in a dress sitting on a chair

The XK Lens achieves Fujinon cinema-quality images.

Many cinematographers feel that you should stick with prime lenses. Especially if you’re using a PL mount, it’s often taken for granted that you’ll be using prime lenses. I suppose the major reason for this is a concern for image quality, as I mentioned earlier. When a lens is equipped with a zoom function, more than a few people feel that image quality will be less than top-notch. In this regard, people often cite things like sharpness and perceived resolution. Then, with zoom lenses, people bring up the point of lens-specific distortions such as barrel or pin-cushion distortion. But in the case of the XK Lens, you have to admit that the image quality it delivers is outstanding—truly on a par with prime lenses. The XK Lens is an all-in-one unit that fully demonstrates the power of cine lenses when examined from all angles—be it skin texture or the ambience unique to cinema—and merits the name of Fujinon. With the present project, I was creating a work in 4K resolution. But I came to realize, as I was doing the editing, that this lens has such awesome rendering power that I found myself totally absorbed in its images. It faithfully reflected the aura radiated by the model’s skin, the texture of her clothing, and the shooting stage—it just created a fantastic atmosphere and mood.

Covers Super 35 mm sensors—quality unobtainable with still lenses

[photo] A cameraman's hand on a follow-focus wheel attached to an XK Lens on a Sony Camera

The visual beauty possible when combining the XK Lens with the Sony PXM-FS7 was beyond my imagination. Mounted via a mount adapter.

[photo] A cameraman filming a woman on the beach

Combined with the Red Weapon. Shot at high speed (100 fps) using a 5K imager.

This time around, I used three cameras. I shot with a Sony PXW-FS7, a Red Epic Dragon, and a Red Weapon. Since the size of the XK’s image circle basically covers Super 35 mm, the 5K sensor size is the maximum size when using the Reds. With 5K, the two Reds support high-speed shooting at 100 fps, so this allowed me to add slow-motion effects. Compatibility with the FS7 was excellent. With that camera, I shot mainly DCI 4K at 60p. By the way, because the lens mount on the FS7 is an E-mount, I mounted the XK on the camera using a PL-mount to E-mount adapter. In this case, I had to attach the lens using a rod-based support system. Anyway, to sum up: it was great to shoot in a stress-free environment without the need to swap lenses during shooting. As for image quality, I have no complaints at all. I think I was able to bring a level of quality into my work that previously would have been impossible with traditional still lenses. In particular, the color rendering is unparalleled. Because its rendering capabilities go beyond surface appearances, I was able to capture images with amazing depth.

Solid operability based on superb body design

[photo] A side profile of an XK series lens on a digital camera

Operability is outstanding thanks to the high level of design that went into the body. Focus torque and angle are also at the highest level of usability.

The high degree of perfection in the design for the cinema lens housing was something I felt was of uniquely Fujinon quality. The industry-standard 0.8 mm gear pitch has been adopted for focus, zoom, and aperture. If you want, you can attach a third-party follow focus with any gear pitch. For this job, I took a chance and added some zoom movement into the shoot. I also used a follow focus to achieve zoom movement that could only be obtained manually. Also, I was impressed with the torque on the focus gearing. It was nice and solid, but easy to adjust. Along with the tight, firm torque, the focus can be adjusted over a wide 200-degree angle. This means the focus can be continually adjusted onto your target. All of the numbers engraved on the housing are extremely easy to read, and camera operators would say that the operability is outstanding. When you’re shooting on location, it’s really important that you can operate with total precision, without making mistakes. Since the advent of high-resolution video production, such as 4K, there’s been a lot of debate about focus. The XK is designed to make it possible to reliably achieve more delicate focusing and extremely precise aperture settings that would be impossible to achieve with a still lens. The housing is extremely robust, and in every component you can see the high level of lens design technology that Fujifilm has nurtured over the years.

Variety of styles possible with a removable drive unit

[photo] A cameraman's fingers on zoom buttons attached to an XK Series lens

Removable drive unit enables a variety of setups to match the shooting environment, such as ENG or cinema.

The XK features a removable drive unit. It’s a servo unit that uses an electric motor to move gears for zooming and so on. It works well when you’re shooting with a shoulder-mounted camera—for example, for one-man electronic news gathering (ENG). It can be attached and detached via four screws that attach directly to the lens body. This way, you can change your shooting style to suit the application. It’s perfect for all-round high-end cameras such as the aforementioned Sony FS7. The consistent T-numbers right across a 20 to 120 mmzoom range, surely expandsthe appeal of this lens beyond cinema to include documentaries and news. The fact that you can use a zoom and focus controller for broadcast applications opens up endless possibilities in on-air broadcast video and live on-location video.

Incredibly cost-effective compared to rival products

The XK Lens is the perfect PL-mount zoom lens, but it’s been designed to be affordable. Standard PL-mount zoom lenses are generally expensive—even renting one can be beyond certain budgets. Having a low-price zoom lens that operates over a wide 20 to 120 mm range without a drop in T-numbers would be a great boon for people who shoot using still lenses. It’d be fantastic if the XK Lens was your first PL lens. After finishing three days of shooting, I came to feel that I couldn’t go back to not using it. The XK Lens represents a new standard in PL lenses—something that was simply unavailable before now. It’s going to be a breath of fresh air in the field of digital cinema.