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

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.

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.

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.

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

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.

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.