First look: Fujinon MK18-55mm T2.9 cine lens
The new Fujinon MK18-55mm T2.9 cine lens is the first of the company’s new line of ‘MK’ series Fujinon lenses aimed at the ’emerging production’ market. These lenses are designed to meet the needs of cinematographers who require features generally found on cinema lenses, who often work in the Super 35 format, and can’t justify the cost of lenses costing tens of thousands of dollars more than their cameras.
According to Fujifilm, the MK lenses are basically a smaller version of its Cabrio series of cinema lenses, which typically cost $ 20,000 or more. The two lens lines share the same coatings and general mechanical design for moving lenses and groups. Between the 18-55mm and the already-announced MK50-135mm lens, the MK line covers the very useful 18-135mm range for Super 35 shooters.
Perhaps the most interesting feature, however, is Fujifilm’s use of Sony’s E-mount standard, which we’ll look at next.
First look: Fujinon MK18-55mm T2.9 cine lens
So why Sony E-mount? Fujifilm already builds high-end lenses for the PL mount favored by film and broadcast studios. But the company wants to address the burgeoning market of independent filmmakers, small production houses, and other professionals using the Super 35 and APS-C formats. Sony has a huge presence in this market, with many professionals using the Sony FS7, FS5, and even a-series cameras. However, there are few dedicated cinema lenses for E-mount, with many shooters using EF-mount lenses via adapters.
This means there’s a huge potential market of professional videographers who can be targeted. Also, since these lenses are built to mount so close to the sensor, they can’t be adapted to mount on PL mount cameras, meaning that Fujifilm doesn’t risk cannibalizing sales of their HK, ZK, and XK range of cine lenses.
First look: Fujinon MK18-55mm T2.9 cine lens
One difference between cinema lenses and most modern photography lenses is that cinema lenses use an all mechanical design. There’s no ambiguity of movement, such as focus mechanisms that keep turning when they reach the end of their range.
Additionally, gearing on lens elements allows the use of accessories such as a follow focus (a geared control that allows fine-grained, smooth control over focus, often relocated to a more convenient position). The gearing also allows motorized control of any of theses rings, if the lens itself is buried too deeply in a rig or placed on a shoulder mount or Steadicam, where direct access is not practical.
The Fujinons both use the industry-standard 0.8 gear pitch, which allows them to be used with the broadest range of existing accessories.
First look: Fujinon MK18-55mm T2.9 cine lens
An important aspect of cinema lenses is that lens sets are often matched so that lenses are the same (or very similar) size and weight, which facilitates easy switching and doesn’t require the entire camera rig to be modified or rebalanced when a lens change occurs. This way, it’s easy to switch lenses while keeping things such as matte boxes, follow focus, or stabilization systems in place.
Lenses in a set typically have the same T-stop to insure perfectly consistent exposure when switching lenses, as well as producing the same color and contrast.
The MK lenses appear to achieve this. The MK18-55mm and MK 50-135mm lenses have the exact same weight, dimensions, front diameter, and filter size, which should make it easy to switch between them without issue.
First look: Fujinon MK18-55mm T2.9 cine lens
The MK18-55mm lens, as well as the upcoming MK50-135mm version, are both T2.9 lenses. Unlike F-stops, which are based on the physical aperture size of a lens, T-stops indicate the actual amount of light transmission for the lens. This makes it possible to switch lenses with the confidence that all lighting and exposure settings will be consistent when a lens change occurs, and that all footage can be matched very closely.
First look: Fujinon MK18-55mm T2.9 cine lens
The focus system of this lens is designed to meet the needs of cinematographers. It has 200 degrees of focus rotation, allowing for very precise focus adjustments using a follow focus system. Additionally, the focus mechanism has hard stops at the end of its range, making it possible to do things like mark positions for a focus pull with no ambiguity about where focus will occur. In contrast, most DSLR or mirrorless lenses continue rotating even after reaching the end of their focus range, making this extremely difficult.
The lens also includes precise distance marks. This may not be a big deal to still photographers, who typically focus through the lens or on an LCD screen, but it’s important if you have a separate focus puller who’s trying to follow the action in a ‘blocked’ scene, where all the action takes place at prearranged distances.
First look: Fujinon MK18-55mm T2.9 cine lens
Another feature that is hugely valuable for video work, yet not generally important for stills, is a parfocal design.
Parfocal zooms maintain focus at the same distance, even when you change the focal length. This is of little value in the autofocus world of stills shooting: it’s trivial to get the lens to refocus after a zoom and before you fire the shutter. But in the realm of video shooting, where the process of zooming the lens may be part of the final product, you can’t afford for the footage to drop out of focus, mid shot.
The parfocal design means, for instance, you can frame a wide-shot of a two-person interview and then zoom-in on one of the subjects, without them dropping out of focus. Both of the Fujinon lenses exhibit parfocal behavior. Zoom can be adjusted using the included lever or via the lens gearing.
First look: Fujinon MK18-55mm T2.9 cine lens
In addition to parfocal design, another desirable property of cinema lenses is that they don’t exhibit lens breathing, a phenomena in which adjusting the focus of a lens slightly changes the field of view at the same time.
As with parfocal design, this isn’t a big issue for most still photographers as only the ‘decisive moment’ is being captured. For cinematographers, however, adjusting focus during a shot is very common (racking between two subjects, for example), and it’s distracting to the audience when this also causes the field of view to shift. As such, the MK18-55mm is designed to suppress lens breathing during focus operations.
First look: Fujinon MK18-55mm T2.9 cine lens
In addition to regular shooting, the MK18-55mm also includes a macro function that makes it possible to focus within a few inches of the front lens element. It’s probably not something most people will use all the time, but if you need a macro shot in your production it allows you to capture the footage without bringing in a non-standard lens.
Additionally, and consistent with being developed alongside studio-quality lenses, the MK lenses feature an adjustment flange to correct back focus. In video circles, ‘back focus’ refers to the distance at which the lens is attempting to focus its image: and perfect performance can require very slight adjustment to correct for any manufacturing tolerances. Studio cameras often allow tiny movements of their mount to ensure the correct lens to sensor distance. Since the MK lenses are likely to be used on cameras without this correction, it’s included in the lens, instead.
First look: Fujinon MK18-55mm T2.9 cine lens
One of the most exciting aspects about the Fujinon MK lenses requires taking another look at why these are going to be E-mount lenses.
In addition to a potential market of E-mount videographers, and Sony’s willingness to share its E-mount specification, there’s another reason we suspect Fujifilm has gone with E rather than EF or PL: the similarity to its own X mount. While the details differ, the flange-back distances of the two mounts vary by only 0.3mm, meaning that any optical design that works for the E-mount should work similarly well for Fujifilm’s X-mount.
In fact, Fujifilm has already announced that X-mount versions of these lenses are being developed for launch later this year, which raises the question: is Fujifilm really expecting owners of current X-mount cameras to spend $ 4000 on video-specific lenses? Or does this lens, and all the work done on developing the X-T2’s 4K capabilities, herald a more substantial entry for Fujifilm into the semi-pro video space?
Articles: Digital Photography Review (dpreview.com)
