A Guide to Portable Wireless Video Transmission Systems

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We are amidst a video-transmission revolution, with new manufacturers constantly entering this crowded field, providing more choices than ever. Low-budget, mid-budget, remote location, and run-and-gun productions now have the ability to match the capabilities of larger, big-budget productions by allowing you to untether from the traditional wired set and allowing your director, AD, or focus pullers to roam free while monitoring your shots—not to mention how much more crowded with technology and equipment production is these days, so removing the wires where you can is always a plus. Let's look at a few features to consider when comparing portable wireless systems.

Teradek Bolt 1000 XT 3G-SDI/HDMI Wireless Transmitter and Receiver Set

Input Resolution vs Transmission Resolution

Though there's a wide variety of wireless transmitter/receiver systems out there, when you're monitoring a shot on set, especially for a detailed director or focus puller, the quality of the image will be important, so cheaping out on a system that only transmits a low-resolution and color depth will probably not meet your requirements. Most professional transmission systems on the market right now support up to 1080p60 and many support HDR workflows, which will suit your visual needs and the requirements of most portable monitors. Another consideration is how many monitors you need to transmit to on set. Many professional transmitters have the capability to transmit to multiple receivers simultaneously; for example, Teradek's line of Bolt 1000 XT transmitter/receivers support transmission to up to four receivers. Many are also compatible with different models within their company lines, allowing you to mix and match transmitter/receiver pairs based on transmission distance, resolution, and encryption support.

SmallHD FOCUS Bolt Sidekick RX

Transmission Distance

When manufacturers advertise their products’ transmission distance, it's often in maximum line-of-sight distance as part of the product name, but you want to make sure that is the case or if it means maximum overall. For example, Teradek advertises its Bolt 500 as having a 500' line-of-sight range, the ikan Blitz 500 advertises 1,230' range, but performs best at a maximum of 500', Hollyland's Cosmo 1000Plus denotes a 1,000' line-of-sight range, and the Cinegears Ghost-Eye 150M denotes 300 meters line-of-sight and provides nearly 500' optimal range. Some products will advertise an eye-popping 3,000' such as the Teradek 3000 XT transmitter that uses powerful 5 dBi antennas to achieve an extreme line-of-sight range, while the Cinegears Ghost-Eye 1000M boasts more than 3,200' line-of-sight, and you can add optional 9 dBi extended range 5G antennas for better signal reception. Sometimes all you need is an antenna upgrade to sharpen your transmission if you find yourself losing signal, so make sure you have that option to swap them out for long-range versions if your production needs change. Antenna considerations can range from how far away from your camera you need your monitor to be to how much space you have for the antennas on your rig. There are also some manufacturers who sell their own wireless systems that perform best with their own cameras, such as ARRI, which offers its WVR-1 receiver that is not only compatible with its external transmitter but also with the wireless transmitters within its cameras, such as the ALEXA SXT W.

Generally, if you're inputting a higher resolution than what you're transmitting, wireless transmitters aren't being used for recording and just for monitoring. But if you desire a backup recording or need to see the same or near the quality of what you're shooting, you will want to find a transmitter that will match your input while transmitting high-resolution, uncompressed video. Most wireless video systems will support up to what's considered "Full HD," or the equivalent of 1080p60, which is suitable for getting the most of your monitor resolution or for backup recording for broadcast, Internet, or smaller video productions. But what about when you'd like to record a high-resolution 4K HDR video backup? What if you're a focus puller on a 4K+ set who needs to see the fine detail image on your monitor, but a 1080p transmission just won't cut it? More high-end products are now being released to support 4K uncompressed video with HDR support, such as the Teradek Bolt 4K, which uses powerful chips from Amimon to send high-resolution lossless video with zero (or less than 1 ms) delay. Since Amimon also provides chips to SmallHD and other wireless manufacturers, the 4K transmission field is bound to grow quickly.

CINEGEARS Ghost-Eye Handheld Real-Time 5G Wireless Video Scanner/Receiver/Monitor

Supported Frequencies and Interference

The majority of wireless systems operate in the free 5 GHz frequency band (it doesn't require permission or a license), but this can pose problems because Wi-Fi and many other appliances and devices also use this frequency. For this reason, video transmission systems all feature selectable and/or automatic frequency channel ranges, as well as DFS and non-DFS frequencies. For example, dynamic frequency selection (DFS) support is helpful when working within busy areas with other equipment running on a 5 GHz band. It will scan and detect whether a signal already has activity and fail over to another frequency. However, this can be disruptive to your transmission if your system keeps dropping and changing frequencies, so using non-DFS frequencies can be helpful to simply choose your channel manually. Though, if your transmission disrupts other systems, this is not playing fair within the environment and can still disrupt your transmission. One solution is to use an external scanner to quickly pinpoint open channels rather than leaving that job to your transmitters/receivers. For example, Vaxis provides an external frequency scanner with its Storm Focus 058 receiver display, and Cinegears makes a Ghost-Eye 5G Scanner/Receiver/Monitor that not only scans different frequencies and visually shows you which signals are the strongest and which are open, it also allows you to switch to a monitoring mode to test the quality of your video transmission. Finding open channels before setting up your transmission system will save a lot of time and frustration in the long run when you're shooting in a busy area.

Hollyland Cosmo 1000Plus SDI/HDMI Wireless Video Transmission System

Cross-Conversion, Loop Output, and Redundancy

As discussed above, if you're on a high-pressure shoot, you'll want to make sure your transmission will not fail to get to its destination. Finding a clear wireless channel is one step, and another is to make sure to have multiple points of redundancy or to add a remote management system (RMS) to your workflow. Because most professional transmitters can transmit to multiple receivers simultaneously such as the Teradek Ace 500, RMS systems such as the Ghost-Eye RMS from Cinegears can input signals from multiple receivers and switch them without any failover time -- so if one receiver fails, it will automatically reroute the alternate receiver's video to the destination.

CINEGEARS Ghost-Eye Redundant Management RMS 1000M Kit

Crystal Video Technology's two-channel Beamlink-Duo transmission kit offers the ability to transmit from two transmitters to one receiver, which sends wired output to two different displays. Other handy features supported by many pro systems with HDMI and SDI inputs and outputs are cross-conversion and loop output. Loop output allows you to output a wired video signal right from the transmitter, such as the HDMI loop out on ikan's Blitz Lite 300, while sending a wireless transmission to the receiver, enabling you to use a monitor close to the transmitter as well as one attached to the receiver. However, if you are using a transmitter with both HDMI inputs and outputs but your monitor has an SDI input, you might want to transmit to SmallHD's Cine 7 On-Camera 500 TX monitor, which features HDMI input and SDI loop output, so you can do a wired cross-conversion to an additional SDI monitor.

Encryption and Security

If you are working on a project with a high budget and what you're recording is sensitive, you may want to invest in a transmission system that supports encryption, a technology that scrambles your transmission until it is decoded on the other end with the right key. Supported encryption on popular pro systems is generally AES-128 or AES-256, which require a matching key on the other end to decrypt the video. This means that both ends—transmitter and receiver—need to support the same level of encryption to secure your transmission or else your transmission will remain scrambled. So, despite manufacturer claims that their units are compatible with "any" receiver or transmitter, you will still have to make sure that both ends support encryption so your transmissions are secure from hackers and prying eyes.

Vaxis Storm 3000' DV Wireless Video Transmitter with Dual V-Mount Plate

Power and Mounting Options

It helps to be prepared with every battery and wired power option that you can, since every manufacturer has their own power requirements for their units. This means that some transmitter/receiver pairs may have different battery requirements due to size and power requirements, some sets may use the same battery, and some may also or only support wired power from a D-Tap or other DC source using barrel, LEMO-type, or even proprietary power inputs. Many manufacturers will also sell transmitters and receivers with optional battery plates, allowing you to choose your own so it fits into your setup with pro power options such as high-capacity V-mount or Gold mount batteries. There are even transmitters like the Vaxis Storm 3000 DV which can cut down space and cabling by featuring a V-mount plate on either side so you can piggyback battery power through the transmitter to the camera.

Mounting the units securely can become a concern when the transmitter and receiver are mobile, so it's important to secure your investment. Most units will feature a 1/4"-20 and/or 3/8"-16 standard thread to mount on a director's cage, follow focus rig, or camera extension, but there are also some that feature metric threading and proprietary mounts. So be sure to keep an eye on size, weight, and mounting type to match your rig setup.

Now that you've got the basic overview of what to consider for portable wireless video transmission systems, check out all your choices on the B&H Photo website and make sure to visit the B&H Photo SuperStore when you're in New York City.

Items discussed in article

4 Comments

I just checked and the ikan Blitz Lite 300 HDMI Wireless Video Transmitter and Receiver System is 100% Identical to the packaging! So you caught the concept...!

Thanks again,

Todd P.

Buffalo, NY

I love the fact that I'm not the only one blown away by what you can do with technology these days.  I was fortunate to get in on the very end of our local school system adding a Jumbotron to their new "Turf Complex".  I was able, 4 years ago, to convince them to run two dual Fiber Runs to the Scoreboard.  For finical reasons we were stuck with 25' HDMI cables between the Fiber send and the camera.  In or second year we did add HDMI over Cat 5e but what a mess to handle during live events.  One company I saw not mentioned was Hollyland Mars 300 Dual HDMI Wireless Video Transmitter & Receiver Set.  It was sub $450 + a "Sony L" series battery on the camera end, Wow true Wireless HDMI (Which although not 3G SDI it works fine) live video (I'm sure there is some delay but from a 50' Screen & back to the field you just can't catch it).  Great article, very informative and well thought out, thank you...

Todd P.

Buffalo, NY

I'd like to buy a set of these to use on my Steadycam while filming events however I have a couple of questions: #1- Are they good and reliable enough for live-event-multi-camera-switching (indoor events/concerts)? #02- Which tally-light system do you reccommand in a 3-7 cameras-switching-live-event-productions? Thx.

Hi Alberto - 

The products featured above are professional grade, designed for reliable, critical professional applications. Please contact us directly for help selecting a tally light system:  [email protected]

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