Brent Ramsey
Brent Ramsey

Brent Ramsey has spent over thirty years in the cinematography field where he has worked on television programs, films and commercials. He is currently a Canon Technical Advisor for our motion picture equipment.

Talking Gear: Dissecting the EOS C500 Steadicam rig accessories

July 23, 2013

I had a chance to shoot with Steven Poster, ASC, on a project for Canon Cine lenses called “Rhythm of Life.” It was a 3-camera, EOS C500 shoot and was the first to use all nine of the current set of Canon Cine Lenses in the same production. In order to showcase the lenses, Steven designed shots using a variety of production tools and camera configurations – a studio build on a dolly, a handheld setup, a camera mounted on a Technocrane, and this Steadicam rig, which was built with the CN-E15.5-47mm T2.8 L S Compact Wide-Angle Cinema Zoom Lens on the EOS C500.

After the shoot wrapped, I started looking at the behind the scenes photos I’d taken and began blaming myself for not taking notes as to what gear we had used on the rigs in this 4K shoot in Los Angeles. Fortunately, I ran into Steve Wong, Steven Poster’s 1st Assistant Camera on the shoot, in Sim Digital’s parking lot shortly afterwards. I showed him the Steadicam rig pictures (shown below; for a larger photo click here) and he helped me dissect the items in this complex build. I also contacted Sim’s Camera Department Manager, Brent Boles, and Andre’ Wright from the Service and Repair department at Keslow Camera for help with brand identification for some of the parts, and I want to thank them for their help.

Certainly, not all EOS C500 Steadicam rigs are this complex or elaborate, nor do they require all of the components pictured. However, for the sake of gear education, let’s take a closer look at what this particular Steadicam solution involved – part by part:

Click on the images to enlarge

Steadicam Operator, Jody Miller, during filming of "Rhythm of Life" with Canon Cine Lenses and the EOS C500.

1. Lockit box

The very important process of multi-camera synchronization begins with time code. All cameras need to be synched to a common time code source prior to shooting and that requires a time code generator – often referred to generically as a “Lockit box.” These units output a crystal signal capable of holding drift to an acceptable half frame a day.

Items 1 and 2 are both time code generators in this image. Since there is only one output on each device, the camera crew is using two generators to ensure that both the camera and the recorder stay in sync with each other and to the other two cameras and two recorders being used without the use of cabling or radio links among them.

One of two time code generators on the rig would have been jam-synced from another master unit. This one is providing time code to the Codex Onboard S recorder. We could not positively identify this device, but I believe it to be the Horita PG-2100 or similar.

2. Denecke Dcode SB-T Time Code Generator / Reader and Tri-Level Sync Box

The Denecke Dcode SB-T reads, generates and jams time code to all the standard frame rates, including 23.976 for High Definition (HD) video. The outputs include time code and video sync in PAL and NTSC, as well as Trilevel for HD shoots. This unit is providing a crystal time code signal to the camera.

3. IDX Endura Elite battery (136Wh Lithium-Ion Power Cartridge V-Mount Battery with Digi-View)

The Endura Elite was developed specifically to support the higher loads and power requirements of HD cameras. This Lithium-Ion battery provides 14.8 volts, 9.2 amp hours and 136 watt-hours of power. Its unique design consists of two identical battery cartridges housed inside a rugged outer casing. Along the top and side of the Endura Elite is an LED battery monitoring called Digi-View -- a 10 step, flashing/solid indication of remaining power that helps the crew keep track of remaining power. It’s especially critical to keep an ample supply of juice to the Codex recorder.

Items 3, 4 and 5 are matrixed together with male/female IDX V-Mount battery plates, which transfer power across the set of components.

The P-V2 V-Mount adaptor plate converts most cameras to a V-Mount battery interface. The P-V2 has a two pin D-Tap on the side for powering an on-board camera light or accessories.

4. RF Film H.264 Low Latency Video Transmitter

Used on films such as “Batman,” “The Amazing Spiderman,” and “Oblivion,” this unit gets its HD/SDI (Serial Digital Interface) video source from the camera and transmits a real-time wireless HD video signal to where it is distributed around the set for things like focus pulling and director’s monitors. An added value in this situation is that it keeps the Steadicam operator from having to be tethered, leaving him to move freely around the set without the usual hassles involved with trailing cables behind.

5. IDX Battery Plate and Power converter

Items 5 and 6 are working in tandem. Together, these items take the battery’s 14.8 volts of power and convert it down to 8.4v for the EOS C500. Connected with Item 6, a passive power distribution amplifier, manufactured by Keslow Camera, is capable of dispensing power to other camera accessories on the rig.

6. C300 “Magic Box” by Keslow Camera

According to André Wright at Keslow Camera, 1st Assistant Camera Steve Wong had used this setup on a previous shoot, was happy with it and secured the part from Keslow for the “Rhythm of Life” shoot. At Keslow, it’s called the “C300 Magic Box” – a proprietary item built by Keslow Camera and used to pass voltage. They actually built one of these Magic Box units specifically for each camera model in-house to accommodate power distribution for each manufacturer’s particular needs. It’s a passive distribution amplifier and includes 5-3 pin connectors to supply power to on-board accessories, like the Preston FIZ (FI + Z) unit, attached to this camera. This item, according to Keslow, is a converted module that they modified to add BNC connectors. It is connected to the camera’s HD/SDI port and supplies an HD/SDI splitter for feeds to the wireless video transmitter and the Steadicam’s “Donkey Box” (Item 15 ).

7. Codex Onboard S Recorder

The Codex Onboard S Recorder can record every mode the EOS C50O outputs, including Canon Cinema RAW, which was used on this three-camera shoot. It is ideally suited for Steadicam work – weighing in at only 2.4lbs/1.1kgs. 

8. Denz Top Handle

This is the standard size Denz Top Handle and contains a 15mm rod slot in the center. It is drilled with 3/8'' and 1/4'' threads for mounting additional camera accessories and mounts with a standard hot shoe mount.

9. Canon CN-E 15.5-47mm T2.8 LS Compact Zoom

Canon Cinema Compact Zoom lenses are relatively new to the film industry, but with their superb optical performance and resolution that exceeds 4K, they won’t be unknown for long. The CN-E 15.5-47mm T2.8 LS delivers a wide to medium range of focal lengths. As part of the new series of cinema lenses, the CN-E 15.5mm-47mm and the CN-E 30mm-105mm T2.8 L S compact zooms are sure to become one of the first choices for Steadicam work going forward.

10. Cinematography Electronics Cine Tape Measure

The main components of the system are the CINE TAPE MEASURE CONTROL and the SENSOR ASSEMBLY. This versatile ultrasonic system continuously calculates the distance between a subject and the camera's film plane. The control displays accurate distance measurements from the constant stream of data that is received by the sensors and by continuously measuring distance during a shot, small or subtle subject movements is no longer a problem. With non-stop measurements, focusing a camera lens is simplified, which saves time, avoids retakes and reduces production costs. It is compatible with all lenses, film cameras and video cameras.

11. Arri LMB-5 Clip-on Matte Box

Once again, the emphasis on this choice of equipment is about weight. The Arri LMB-5 Clip-On Lightweight Matte Box weighs only 10.4 ounces with two 5x5.650 filter trays. Using a series of special master and step-down rings, it fits practically onto any lens and is a favorite for handheld and Steadicam work.

12. Preston DM-2 Digital Zoom motor (FIZ)

The DM-2 motor is attached to 15mm rods and controls the lens’ zoom range. This unit is a smaller and lighter version of the original DM-1 and is intended to perform focus, iris or zoom functions on all but the stiffest cinema lenses. 
The motor can be mounted to a variety of swingarm brackets with conventional 15mm rods or directly mounted to matte box support rods.

13. Arri Lens Support LS-10 for 15mm rods

The Arri LS-10 clamp-on Lens Support fits industry standard 15mm Iris Rods and has a captive 3/8-16" threaded hand screw that attaches to the Lens Mounting Bracket.

14. Cine Tape interface cable

This connects the Cinematography Electronics Remote Controller to the Preston MDR2, enabling the display of the focal distance on the handset remote controller (not shown in the picture).

15. Preston MDR2 Motor Driver for FIZ system

The Steadicam operator has enough on his plate just operating the camera, so focus and iris adjustments are performed remotely with this neat little unit and its components. The MDR2 Motor Driver interfaces the FIZ Hand Unit with the DM-1, DM-2 and DM-3 digital motors. It provides three channels of motor drive, the camera-run function for film cameras and the video tape recorder (VTR) function for video cameras.
The unit automatically calibrates the motors to the mechanical end limits of the lens. Each of the three channels has a separate three level torque limit selected by a switch.

The FIZ system controls the complete array of both lens and camera functions. The system is modular, giving the user a wide range of choices from a basic cable connected system to a full wireless microwave system. The system consists of the Hand Unit (not shown), Motor Driver, Digital Motors, cables and motor mounting bracket.

A bright bar graph display shows the position of the zoom lens. The zoom function is implemented by a Micro Force control and can be directly connected to the Hand Unit using a bracket or operated remotely using a cable. The camera may be started either from the Micro Force or from the Hand Unit. An optional Remote Iris Box provides a separate control for the Iris function.

16. Arri Sliding Baseplate with Bridge Plate adaptor BP-13 for 15 mm rods, compatible with the adaptor plate for the EOS C500.


17. Denz C300 Baseplate

German company Denz makes this neat little baseplate for 15mm rods, which raises the height of the camera body to conform with standard industry accessories. Left and right serrated rosettes allow for the attachment of handles and other accessories directly to the baseplate.

18. Vocas Universal Recorder bracket

This is a very flexible universal recorder bracket and was being used to securely mount the Codex Onboard S Recorder to the rig.

19. Element Technica 18” 15mm Ultra Rods™

Element Technica's Ultra Rods™ are plated with nickel over aircraft grade aluminum tubing, which produces an iris rod with the low weight of aluminum but the surface durability and ease of operation of stainless steel. While they are strong enough for most zooms, they weigh in at one third the weight of stainless steel.

20. Donkey Box for Steadicam Pro

The Donkey Box is the connection point between the camera rig and the Steadicam. It’s where fine-tuning adjustments are performed to balance the camera rig on the Steadicam. It also contains a power and video distribution box.

According to Charles Papert on HomeBuilt’s Steadicam forum, Camera operator and director of photography, Chris Haarhoff, was the originator of the term "Donkey Box," which he later shortened to "D-Box." It refers to the 3A replacement top stage he designed, which was incorporated into the Steadicam PRO. He claims that he randomly made up the term as a response to the boring and obvious names of Steadicam parts that preceded it!

The D-Box, which is at the base of the sled, stands for “distribution box.” It’s where all the main power and video is distributed between the Steadicam’s lower components before it reaches the “J-box.” The J-box or “junction box,” then re-distributes power and video to other input and output connectors on the Steadicam unit.

Special thanks to:

Steve Wong

I.A.T.S.E. Local 600

1st Assistant Camera, Los Angeles


Brent Boles

Sim Digital, Los Angeles


André Wright

Service and Repair

Keslow Camera, Los Angeles

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