Reviews |Hollyland Cosmo C1 Review

Hollyland Cosmo C1 Review

Hollyland Cosmo C1 Review

Price when reviewed


Check current price

Our Verdict

Wireless video transmission systems have traditionally been both expensive and complex. There has, of course, been cheap solutions, and some of these, including previous Hollyland models, have been pretty good. But nothing compared with the quality and features set of the Cosmo C1.

The cost of the Cosmo C1 makes this video transmission system incredibly affordable, and when it comes to use, there’s nothing to it, just plugin, and you’re ready to go.

I’ve been testing the Cosmo C1 for a couple of months, and it has become invaluable. I’ve been connecting the system to my 2nd camera, and then I’m able to keep to eye on what’s being filmed from a distance.

Couple the Cosmo C1 with a Zhiyun Crane 3S, and while the two don’t communicate directly, I’ve been able to use the visual transmitted from the Cosmo C1 while adjusting the camera’s position with the Crane 3S.

OK, this is possible using the Zhiyun video transmission module, but there’s a huge difference in the latency and the quality of video transmission.

The quality of the 1080p video transmission is excellent, and you really cannot see any delay between what’s happening and what’s on screen.

Because of this, the Cosmo C1 can be used by focus pullers with a clear visual being beamed back to enable refocus without the need to be with the camera. A focusing system is of course needed to complete the setup.

If you use more than one camera for video, the Cosmo C1 is a superb and easy to use solution that I would highly recommend.


  • Compact
  • High-quality build
  • Easy to use


  • Live stream function needs work

What is Cosmo C1?

If you use multiple cameras, you’ll know the issue, especially if there’s just one of you. You get the cameras set up and positioned, hit record, settle behind the main camera, and then intermittently check on the other one or two, if at all.

If you’re lucky, you’ll have someone operating the other two cameras, but even so, if you’re directing the shoot, you’ll want to keep an eye on proceedings.

The Cosmo C1 enables you to do exactly that. Plug the transmitter into a camera, and then the video signal is beamed back to the receiver. The receiver then feeds into a monitor so you can see what the camera sees, and then adjust as required.

Hollyland Cosmo C1 Review

The COSMO C1 will revolutionise the way you shoot video.

As with any wireless mic system, you have a transmitter and receiver. Link the transmitter into the camera and the receiver into a TV, monitor or recording device. Then a 1080p signal will be beamed between the two.

What makes the Cosmo C1 stand out is the ability to link the receiver to your computer directly. By doing this, you can directly livestream to your chosen platform so that you can be out handholding your camera around an event while at the same time live streaming at a resolution and quality far higher than you would get through other systems.


  • Wireless Range: 1,000ft (Line-of-Sight)
  • Channel Bandwidth : 20 MHz
  • Frequency Range : 5.1~5.8GHz
  • Latency : As low as 0.04s
  • Wi-Fi : NO
  • Transmitter Video Connectors : 1 x HDMI Input, 1 x SDI Input, 1 x SDI Loop out
  • Receiver Video Connectors : 1 x HDMI Output, 2x SDI Output
  • Transmitter Other: I/O 1 x USB Type-C, 1 x DC Power Input
  • Receiver Other : I/O 1 x USB Type-C, 1 x DC Power Input
  • Embedded Audio : HDMI
  • Max Transmission resolution: 1080p
  • Max Transmission frame rate: 60fps

Build and Handling

Arriving in a solid plastic carry case akin to those made by Peli, the Hollyland Cosmo C1 has an instant feel of quality. Opening up reveals the transmitter (TX), receiver (RX), and the power supply and choice of antenna.

Both the TX and RX look similar by design and are only identifiable by the small blue badge for the RX and red for the TX. Lifting them out you instantly get to feel the quality of these small units.

OK, the cost is almost £800/$800 for the set, but still, that’s a fraction of what you’d normally expect to pay for a wireless video transmission system, especially a couple of years ago.

The casing for each unit is made from machined aluminium; this reinforces the quality look and feel.

Hollyland Cosmo C1 Review

Starting with the TX, you have two mounting options: a 1/4-inch thread on one end or a cold shoe mount on the base. On the other end are the ports for the two antennas.

Here you have a choice of the standard or mushroom antenna. The standard is used in most scenarios; the mushroom antenna is used if the TX is positioned lower than RX.

On one side, you have the power input, SD/Out and SD/In and an HDMI. On the other side, you have a small screen, a toggle dial to switch through settings, an on/off switch, and a USB Type-C port.

Looking at the RX and the layout is very similar with the only visual pointer separating the two being the badges and the TX has the cold shoe mount bolted into the base. The receiver also has a difference with two SDI out that enables a loop out if required.

Setting up the Cosmo C1

Setting up the Cosmo C1 only takes a couple of minutes. First, the standard antenna is screwed in. During this test, I didn’t find a situation where the signal strength wasn’t sufficient or the height difference deemed the need for the mushroom antenna.

Once the antenna is in place, the transmitter can be slotted into the camera’s hotshoe, an HDMI plugged in and inserted into the camera. Finally, a Sony NP-F Type battery can be clicked into the top.

Hollyland Cosmo C1 Review

Next, the RX is mounted on a micro tripod then plugged by HDMI into a monitor, and again an NP-F Type battery is inserted. Now all that’s left is to power on.

Switching the transmitter and then the receiver on and moments later the monitor shows that the connection is made.


Due to the price and complexity, wireless video transmitters were out of reach to everyone bar high-end professionals. Now, however, with the likes of the Cosmo C1, these devices are affordable to anyone, although still at a cost. While affordable it does mean that some features such as setting monitoring compatibility with broadcast control units and other professional gear isn’t a feature. But then if you’re using broadcast kit then you probably won’t be looking at the Cosmo C1.

Hollyland has essentially created a transmission device designed for use by today’s emerging video market, small productions that need professional tools.

The wireless system uses the 5.1-5.8GHZ bandwidth and utilises Hollylands proprietory HEVO chip to enable automatic channel switching. This means that if you have several people at an event, using similar devices, the Cosmo C1’s HEVO solution will find the channel that’s clear for the paired transmitter and receiver, and switch to it.

Hollyland Cosmo C1 Review

Essentially like the scan feature on many wireless mics, the HEVO solution finds the cleanest channel to ensure the smallest amount of interference possible.

As the system is based on radio frequency rather than Wi-Fi, unlike cheaper systems, the signal strength is far stronger. This means you can be quite some distance from the transmitter, up to 1000 feet (300m), and still receive a signal.

That video signal is transmitted at a full 1080p at up to 60fps, which is impressive and more than enough for monitoring what’s being shot.

Hollyland Cosmo C1 Review

The next big feature is the Embedded UVC for direct livestream. This enables you to plug a USB Type-C cable into the receiver and then plug that into your computer so the feed can be used to stream video content live.

When it comes to connecting to the video feed from the camera to the TX, this can be done in one of two ways; the first is through standard HDMI, and the second is through SDI. Most DSLRs and Mirrorless cameras offer HDMI, and it’s only when you take the step-up to professional camcorders that SDI starts to come into play.

The HDMI option is simple plugging directly into the TX and out of the RX, whereas with SDI on the TX, you have SDI in and SDI Loop out.

Another nice feature is that there are several power options; the first is the ability to plug the TX or RX into the mains so that the devices are mains powered, although there’s only one adapter in the box.

The next two options are more suited for use out in the field. The first is USB Type-C, where power can be passed directly from a USB power bank into the units for power. At present, I can’t think of any cameras that enable this feature, unlike many camcorder power solutions, so a separate power bank would be needed.

The final option, and the one that I opted for in this test, is to use an L-Series, Sony NP-F battery; these lock-in and click into place.

Finally and most importantly when it comes to features, the latency is close to zero, or 40ms, in the best-case scenario. This means that what you see through the transmitted HD video is essentially happening in real-time.

This speed of video transmission is made possible by the high-efficiency H.265 encoding, making it a great solution for monitoring and focus pullers.


Hollyland has aimed the Cosmo C1 as an entry-level Video transmission systems. Still, there are a few hints at more advanced features and equipment compatibility with the inclusion of the SDI connectors.

Arriving in a compact plastic case, you instantly feel that by owning and using the Cosmo C1, you’re taking your video production to the next level. Taking the units out and the full metal casing gives them a real feeling of quality, attaching them to a tripod, camera and monitor then linking in the cables and slotting in the batteries it all couldn’t be easier.

Hollyland has thought carefully about the end-user; we’re photographers and videographers, not broadcast engineers.

Hollyland Cosmo C1 Review

Switching on there’s little to think about; the units come pre-paired, so once on, the system fires up, and the transmission starts.

Used as a straight video transmission system, they couldn’t be easier to operate. To put it into context, there is no difference between linking in a standard field monitor with a cable than there is with the wireless connection between the two Cosmo C1 units.

In use, the Cosmo C1 is faultless; the TX and RX just work connected from the Sony A7 III to a 7-inch monitor. The feed is bright and clear, and the ms of latency is unnoticeable.

As the feed comes through at 1080p 60fps, the quality is superb and connected to the Sony A7 III, and then FS7, the quality of the video is exceptional.

Hollyland Cosmo C1 Review

Hollyland suggests that the TX and RX are at least 5 feet off the ground for maximum signal quality; for the most part, during the test both cameras and the receiver were tripod-mounted, so this wasn’t an issue.

At a live event, I did beam the footage back to an ATOMOS from a gimbal-mounted Sony A7 III. In this situation, I switched the standard antenna for the mushroom antenna and had no issues with the signal.

In most shooting situations through the test, I was rarely more than 20 meters from the receiver, and the signal strength was always good.

Testing that signal strength out by walking a distance down the road, I got to around 250m before the signal started to weaken, so a little short of the 1000 feet (300m) stated by Hollyland. However, this test was carried out in an urban street with plenty of obstructions and surrounded by houses. Taking that into consideration, that signal strength is impressive.

Overall, the Hollyland Cosmo C1’s quality and performance has been outstanding. The only issue I have had is with the live streaming potential, which I will update the review with later.

Final thoughts

Wireless video transmission feels like a real luxury for a small production, but it has been incredibly useful in a series of situations. The first at an events where I have had more than one camera running. The ability to beam the footage back to a single location makes things so much easier.

Then there is the ability to transmit the footage back to an external recorder or monitor so that if you have others working with you, you can sit and monitor what is going on.

Hollyland Cosmo C1 Review

The other use is for remote focus pulling; the transmission speed means that the Cosmo C1 can be used as an accurate preview for getting focus. You do, of course, need a focus pulling device attached to the camera, but the Cosmo C1 will keep you updated with that all-important point of focus.

In use, the Cosmo C1 really couldn’t be easier to use, it is simple, and some professionals may find the lack of some features and expandability limiting. Still, for most of us running small productions, the C1 is an ideal solution.

Wireless video transmission is a bit of a luxury, more so than wireless microphones. Still, once you’ve started integrating them into your workflow, the benefits are easy to see.

The biggest benefit that I found was the ability to monitor my second camera from a distance. That ability to see the video feed in real-time and adjust the camera’s position and pull focus enabled me to control what would have otherwise been impossible.

Hollyland Cosmo C1 Review

The Hollyland Cosmo C1 is a fantastic simple video transmission system. Used directly as a way to beam video from one camera to a monitor or recording device, the workflow and performance are flawless. When it came to live to stream, I did have a few issues and will update my review soon.

Ultimately, the Hollyland Cosmo C1 is a fantastic video transmission system and well worth the investment.

(function () { var s = document.createElement('script'); s.type = 'text/javascript'; s.async = true; s.src = ""; s.onload = function () { m101.init({ shopId: 928, market: 'gbp_en', geolocation: true, externalPartner: 1}); }; var x = document.getElementsByTagName('script')[0]; x.parentNode.insertBefore(s, x); })();