How to work without batteries


Julian Hiorns TV-Bay Magazine
Read ezine online
by Julian Hiorns
Issue 86 - February 2014
Camera and monitor batteries - what's not to like? They're portable, rechargeable and easy to use. Well, actually, there are some drawbacks. Batteries can be heavy, expensive to replace and difficult and costly to travel with, as airline passengers know all too well. This last issue has become particularly significant since the advent of lithium batteries. Batteries also have a limited lifespan and become less efficient over time, even with the best of care. For serious operations, you have to carry a back-up unit, and this can mean extra cost and weight.

Of course, when you're roving in iso-cam mode or working wirelessly, batteries are the only option, but for operations with OB trucks, stage shows, sports arenas, studio recordings and the like, a battery can be an awkward encumbrance, especially if you have to carry a heavy duty type for extended running time. As time goes by, batteries are becoming smaller and lighter, but they are still expensive and high-maintenance, and the transport limitations will be with us for a long time to come.
The traditional alternative to batteries has been to run power cables directly to the camera or monitor. For most equipment, this has obvious disadvantages, not the least of which is power loss over distance. For example, if you want to run dc power to a camera over a distance of 100m (350ft), you need to use heavy-duty cable to ensure that the voltage drop doesn't become significant. This adds to the "drag" on a camera and makes operation less mobile. The same limitations apply to the powering of monitors. An alternative in this case is to run mains to the monitor and use a local power supply, but this can have safety and installation implications. Monitors (and some pov cameras) may be mounted on gantries or other metal frames, and these have to be grounded to ensure safe operation. Cabling can be cheaper than batteries, but it's a less than satisfactory solution.

Is there an alternative? Now, for all copper cable operations, there is. The concept of POC (Power Over Coax) has been around for a long time and is widely used in the security industry. It's simple enough in principle - the coaxial cable used to transport the video signal is also used to carry dc power to the camera or monitor. Traditionally, POC has been used for fixed installations (such as in shops and stores) and so has not been designed for the demanding type of mobile operations found in broadcast applications (especially in live events).
BHV Broadcast has designed a product known as Video Ghost, which is a broadcast industry version of POC. Video Ghost is a compact and cost-effective portable system for use with cameras, monitors and similar equipment. It allows the user to run dc power and serial digital video (SD / HD / 3G) over the same coaxial cable. With a good quality cable, operating distances of 150m (500ft) can be achieved, depending on the video format. The video path can run in either direction, so Video Ghost can be used to carry power and video to a monitor or to carry power and video from a camera.

The system consists of a power transmitter and a power receiver. When the two are linked with a coaxial cable, the transmitter detects the presence of the receiver and starts sending power over the cable. At the same time, the active video link is established. If at any moment, the link between the two units is broken, the transmitter shuts down, and will only restart when the link is restored. The linking process is automatic, so Video Ghost is a true "fit and forget" system. In other words, the camera and its power receiver can be installed in difficult locations. Should the link be interrupted for any reason (such as in the event of a cable being disconnected)), power will be supplied to the camera once again as soon as the connection is re-established.

Video Ghost has been designed with safety in mind, so there is a multi-layer system of cable interlocks in place. In the event that the user should make an error in the connection, there is no risk to any of the associated equipment. It runs from any standard dc power supply (including batteries!) in the range 10V to 19V, and can deliver 65W at 150m over any good quality coaxial cable.

The eye-catching red transmitter and the blue receiver are intended to make the set-up process as easy as possible by avoiding any confusion between the two boxes. The receiver can also be fitted with a battery plate, so can be clipped directly on to the camera back.

In short, Video Ghost is the video equivalent of phantom power for audio.


Tags: iss086 | Julian Hiorns | BHV Broadcast | Batteries | monitor Batteries | camera batteries | video ghost | Julian Hiorns
Contributing Author Julian Hiorns

Read this article in the tv-bay digital magazine
Article Copyright tv-bay limited. All trademarks recognised.
Reproduction of the content strictly prohibited without written consent.

Related Interviews
  • PAG talk about flying with batteries at IBC 2014

    PAG talk about flying with batteries at IBC 2014

  • PAG Batteries at NAB 2014

    PAG Batteries at NAB 2014

  • Blueshape Batteries at IBC 2013

    Blueshape Batteries at IBC 2013

  • IDX at IBC 2016

    IDX at IBC 2016

  • AntonBauer at BVE 2015

    AntonBauer at BVE 2015

  • KITPLUS rig setup at IBC 2014

    KITPLUS rig setup at IBC 2014

  • Polecam talk accessories on BroadcastShow LIVE 2013

    Polecam talk accessories on BroadcastShow LIVE 2013

  • Anton Bauer at NAB 2012

    Anton Bauer at NAB 2012

  • PAG at IBC2011

    PAG at IBC2011

  • Anton Bauer at IBC2011

    Anton Bauer at IBC2011

  • Brickhouse Video at IBC2011

    Brickhouse Video at IBC2011


Articles
An Epiphany Moment
Peter Savage 2 I had been negotiating the sale of my company and had reached the really hard end of the bargain. We were close to agreeing the final sum after a lot of too-much-give-and-not-enough-take negotiation. The solicitors were calling me, keen for a deal. It had come down to one sticking point and, in my hard ball “I am the Wolf of Wall Street” guise, I wasn’t going to let it go. It would make a value difference of 1.5% on the total outcome. Not much, you might think, but I had already nearly fallen out with the solicitors over their fees and I was giving my advisors an extremely hard time because the corporate adviser couldn’t see how I had already given more than an inch and the buyers were taking more than a mile. I was not going to let them win.
Tags: iss134 | azule | finance | Peter Savage 2
Contributing Author Peter Savage 2 Click to read or download PDF
Using Wireless Transmission
Jeremy Benning Wireless acquisition is a staple of live sports, entertainment and reality shows where cable free capture permits shots not previously possible, for health and safety reasons, and gives the camera-operator greater artistic licence to roam. The same is increasingly true of narrative drama where cinematographers are keen to work handheld or Steadicam where that helps tell the story. Any equipment which frees their movement and time by being lighter, easier to use and reliable in performance is going to tick a lot of boxes.
Tags: iss134 | wireless | 4k | transmission | Jeremy Benning
Contributing Author Jeremy Benning Click to read or download PDF
Shedding Light on the Blackmagic Pocket Cinema Camera 4k BMCPP4K
Garth de Bruno Austin “What is it about light that has us craving it?” Is the question asked in the opening seconds of Garth de Bruno Austin’s latest short, The Colour of Light. Exploring this natural, human need as well as our innate desire to control it, Garth’s film showcases everyday people going about their lives in differing degrees of luminance, whether that be an artificial streetlight or a natural morning sunrise.
Tags: iss134 | blackmagic | cinema camera | 4k | cpp4k | Garth de Bruno Austin
Contributing Author Garth de Bruno Austin Click to read or download PDF
The brave new world of software based production
Boromy Ung In today’s rapidly evolving broadcast industry, the only constant media organizations can truly count on is change — and the need to adapt as rapidly and cost-effectively as possible. One of the biggest agents of change is the IP revolution, driving broadcasters to migrate their operations to all-software solutions running on commodity, IT-based technologies.
Tags: iss134 | chyronhego | graphics | sports | ott | Boromy Ung
Contributing Author Boromy Ung Click to read or download PDF
Sony HDC-4800 Review
Andy McKenzie First announced at NAB 2016, the Sony HDC-4800 is a studio camera system capable of shooting 4K/UHD at up to 8x or full HD at up to 16x. With a price point upwards of £250,000 it is a very high-end product with a wide feature set. In Sony's own words, "This is the future of live production, designed to satisfy the storytelling aspect of modern sports production.” Deliveries began in mid 2017 and, after careful preliminary evaluation, we invested in several systems for our hire fleet ahead of the FIFA World Cup in Russia.
Tags: iss134 | review | hdc-4800 | sony | finepoint | Andy McKenzie
Contributing Author Andy McKenzie Click to read or download PDF