4K Cine Lens Zooming, Without Another Mortgage!

A Look at the Chrosziel CDM-MK-Z zoom motorization unit for Fujinon MK T2.9 lenses

By John E Fry (SOA, GTC)

When Kurt from Chrosziel first got in touch with me to see if I’d be interested in testing out their new zoom servo unit for the fantastic Fujinon MK cine zoom lenses, I was very interested to see what it could do, but must admit to being a little skeptical as to the usefulness of such an add on. After all, the zoom ranges on the MK 18-55 and 50-135 lenses are not massive like broadcast lenses, so would a zoom servo on them be worthwhile?

Lighting Cameraman and Steadicam Operator John E Fry BA (hons) from Salisbury, Wiltshire UK based Fryfilm Productions Limited, Photograph by John E Fry BA (hons)

Simple Setup of the Servo Unit CDM-MK-Z

Photograph by John E Fry BA (hons)

Opening the unassuming Chrosziel box reveals a straight forward set of components: the very compact and solidly made self-contained motor unit itself, a D-tap to Lemo power cable, a jack to jack Lanc cable, an extension cable for that, a USB thingy for updates and an Allen key.

Attaching the motor to the MK lenses is very simple, just two screws fitted with the Allen key, then simply attach the D-tap cable from your battery to the motor, and the Lanc cables, one to the camera remote port and the other from your Lanc remote, in my case this was the FS7’s hand grip. As soon as the motor is powered on it automatically calibrates itself to the lens, very quickly finding the end stops of the zoom ring by rotating it from wide to tele & back a couple of times. With that done you are all set, it’s that quick and easy!

With the motor attached and calibrated, is it really as easy as simply using the zoom rocker on the grip or demand? Yes, it certainly is, and with all the variable pressure speed and precision of an ENG lens servo clamshell, with a beautifully smooth acceleration from stopped to whatever zoom speed you like.

I didn’t realize this initially, but there are three different modes built into the motor. They are:

  • EB / Documentary,
  • Silent, and
  • Live / Hard Cut Mode.

You can choose the different modes by pressing the zoom rocker for round about 5 seconds, then the green LED flashes very fast while changing the zoom mode and after that it blinks 1, 2 or 3 times* – depends on the zoom mode you chose (* 1 = EB / Documentary / 2 = Silent / 3 = Live / Hard Cut). To cycle through these all you need to do is hold the zoom rocker down one way for a couple of seconds to switch to the next mode, and the other way, hold to reverse. I haven’t experimented massively with the different modes as I found out of the box the motor gave me everything and more that I’d hoped for, so rather forgot about the other modes!

The Servo Unit In Use

So however simple to setup and smooth the motor is, does the range on the Fujinon MK Zooms make good enough use of it with their comparatively limited ranges of 18-55 & 50-135? Well, having shot with both lenses in various situations now, I would have to say definitively yes. Even the 18-55 as a conference wide can be made wonderful use of with the Chrosziel zoom, taking us from a big wide to a medium shot very slowly & smoothly to start a show, or an accelerating zoom out when the audience applaud, to the creep zoom in during a key speech, then nice constant zoom out to end the show. I found we were using the zoom much more than I’d expected to, not just because it was there, but because it allowed such smooth zooms we could reframe and offer a lot more than just full wide or full tele, while on shot! This made the experience of shooting a conference more interesting, and gave the vision mixer & editor more options from that angle.

Photograph by John E Fry BA (hons)

Filming in more mobile environments the lenses really show their usefulness. In practice 18-135mm is all the range you really need for most situations, and due to their wonderful sharpness and bright T2.9 constant apertures, this pair of Fujinons really could be the only two lenses you ever need for 90% of shoots. I’d add a big wide like the Sony 10-18mm f4 and a long zoom like a Nikon 200-400mm f4, but those are only for specific shots. For the past couple of years, I’ve been using Sigma’s 18-35mm & 50-100mm f1.8 lenses, which have been wonderfully bright, and sharp, but after using the proper parfocal, geared and properly measured Fujinons, which have longer range, macro ring and are only a stop darker, I’m sold. The Fujis are also about half the weight of the Sigmas (despite being four times the price). The 18-55 and 50-135 are both the same size & shape, meaning swapping between the two is unusually quick and easy. Moving the Chrosziel motor from one to the other takes under a minute, just undo & rescrew the two Allen bolts & swap the cables, so even if you only have only one motor to share between the two lenses it really isn’t a bother to move it between them.

Photograph by John E Fry BA (hons)

From 18 to 55 millimeters is the difference between wide and medium shot, and 50 to 135 is a nice mid to a very useful closeup. The Fujinons both focus very close, thanks to their macro focus ring behind the iris, and a good zoom can make wonderful use of this for drawing attention to close detail. For headshots or interviews, the 50-135 especially makes a wonderfully smooth background, thanks to it’s curved iris blades, so the bokeh is to die for. Add the Chrosziel motor & you have the ability to creep very very slowly in or out from a headshot to emphasize a significant thing they are saying by zooming in, help isolate them in the frame by pulling out, or perhaps imply more meaning one way of the other with gradual inclusion or removal of dead space around them.

If you’re shooting an interview & need to change shot between answers, zooming from the back of the camera smoothly without having to let go of the focus or iris ring to compensate for reframe differences saves time and worry. Both the lenses are incredibly useful for the bright T2.9 aperture, and being as sharp wide open as they are at f8 means there’s no compromise at whatever focal length you want in whatever situation you find yourself in, and the CDM-MK-Z motor makes moving between those focal lengths a constant joy. Having a super smooth zoom also means you can reframe a little while on critical shot if you’ve set up quickly & find composition would be better just a few mil wider or closer, & this is super useful too.

The CDM-MK-Z: On Steadicam

When instructing new Steadicam Operators we only mention zoom in passing, mainly because if you want a closer shot of something when filming with a moving device you usually just move the camera closer to the object. However, zooming on Steadicam is something we actually do quite often, particularly in the broadcast & sports worlds. With 2/3” cameras we have nice servo zoom lenses from Canon & Fujinon which we can attach a nice small zoom demands to, that allow us to operate the zoom from our Steadicam gimbal handle. This maintains the isolation required between the operator and the camera, but gives us control of the huge zoom power of those lenses while we are in motion. For larger chip cameras like the Sony F55, FS7, C300s & Alexas our only options for smooth servo zoom lenses, until recently, have been incredibly expensive ENG style PL mount zooms, or little DSLR lenses with an internal jerky zoom motor, like Sony’s very useful 18-105mm f4. Now we have the much more affordable Fujinon Cine Zooms, suddenly the ability to zoom them when on the Steadicam with the Chrosziel motor becomes automatically integral to your toolbox. Because the motor uses standard Lanc protocols you can easily find a Varizoom or Sony’s own Lanc zoom demand that fits very nicely onto the Steadicam gimbal handle, right where your thumb can do all the zooming easily.

Photograph by John E Fry BA (hons)

Zoom can be very useful on Steadicam in many situations, and not just because using a zoom lens means we don’t have to change lenses, and therefore rebalance the whole rig, as often as when using primes. Filming sports is the obvious application for zooming when on Steadicam, but they have ENG cameras & B4 servo zoom lenses for that. The Fujinon lenses & larger chip cameras are designed more for digital film and TV drama applications, and actually the occasions when zooming on shot when on Steadicam in these situations actually occur more often than you might think. I have zoomed out very slowly while preceding characters on Steadicam for a drama to pull out to show the environment without having to alter my or their pace, for example. This can also artificially accelerate or decelerate the talent or my movements without complicated rehearsal of our relative speeds. I have zoomed in quickly when rounding a fast corner to increase the shock element in a horror, and zoomed out during a track with a character running through a park to increase his feeling of isolation without having to run diagonally away from him. Because your movement and what you are doing with the Steadicam physically are so symbiotic, only the operator has the ability to make best use of a zoom, so being able to zoom yourself, without using a remote motor controlled by an assistant, on Steadicam is a really important option to have, and the CDM-MK-Z makes this a reality for lenses of the quality we want to use for 4K programme & film making.

A Zoom is it’s own Shot

We all know wide, medium, close up, pan, tilt, Dutch, etc. but people often forget that a zoom is it’s own type of shot. It can imply so much about a scene, in a similar way to a dolly in or out, but has a difference that suits a lot of narrative situations, and can save a lot of time and money. Zooming instead of a dolly shot sometimes can be use useful, because it’s quicker and easier to do, you don’t have to physically transport, build a track or dolly, push or pull the camera & operator, or change focus during the move. By zooming, you get a very similar effect, but with parfocal lenses (as the Fujinon MK Zooms are) there’s no need to pull focus, as they maintain their focal distance during the zoom. So suddenly we see that being able to zoom smoothly and precisely during a shot can actually save a lot of time, and money, especially on a drama shoot where the only other way to get a similar effect would be to physically move the camera.


For everyday shooting, even on dramas or situations where you might otherwise use prime lenses, the Fujinon MK zooms are now my number one choice of glass. In two very lightweight, precise and beautifully sharp lenses you can replace a whole box of primes, and save half the weight of equivalent cheaper zooms. Add to these great lenses the Chrosziel Zoom Motor, and you have an incredibly versatile and immensely usable system that can not only cover all the bases in terms of focal lengths, but also zoom smoothly between them in a way only the top end broadcast lenses can. In fact, I would argue the Chrosziel motor gives us a little more than traditional ENG clamshell in its three modes, and really very smooth acceleration and deceleration at all speeds. For Steadicam use, all you need is a cheap little Lanc zoom demand on your gimbal for fingertip control of the zoom without affecting your normal operation or even balance in any way. The motor is so light you’d never even think of removing it to save weight on a Steadicam setup. The ability to zoom as smoothly as you are moving definitely opens up some really great creative options for Steadicam, which I think is brilliant.

If you own one or both of the Fujinon MK Zoom lenses, you’d be mad not to at least have a look at the Chrosziel CDM-MK-Z motor. It is very small, compact and does everything you need of it (and more). I was very surprised at how easy it was to install on the lenses and calibrate, which was done before I even noticed it moving the zoom ring! I’m sure you will find, as I have, that the ability to zoom smoothly and precisely on the MK lenses becomes just as useful and integrated into your shooting style as it is for cameramen who use B4 cameras. Finally, we have a realistically priced, beautifully made and overperforming zoom motor unit for two fantastic, lightweight professional lenses for 4K filmmaking. I can see the motor never leaving the Fujinon MK zoom lens, and the lens almost never leaving my FS7!

Photograph by John E Fry BA (hons)

John E Fry BA (hons)

Lighting Cameraman / Steadicam Operator

Fryfilm Productions Limited

Salisbury, Wiltshire UK

Email: john@fryfilm.com

Twitter & Instagram: @The SteadicamMan