Hollyland Mars 300 and Cosmo 600

Test report opening Hollyland Mars 300 Cosmo 600

Today we have the opportunity of testing two products from Hollyland that will make producing much easier for us. These are video transmitters Mars 300 –home version- and Cosmo 600 –professional version. Let us look at them in more detail.

By Yeray Alfageme, Service Manager at Olympic Channel

Mars 300

The first thing worth noting in the home model -Mars 300- is its name. ‘300’ means that it has a reach of 300 feet, or 100 meters. This already gives us an idea of the big effort made by Hollyland in providing its systems with reliability and range exceeding normal parameters.

This system is intended for production environments and can be easily fitted on ENG, DSLR video cameras or even on a steadycam or a gimbal in order to prevent cables from being connected to a camera from hampering our freedom of movement.

In the box we found a transmitter and a receiver, both made of aluminium and really small. Although wider than a present-time smartphone, they are smaller in size and very light. A good example of the reliability Hollyland has sought to achieve in this system is the possibility of powering it either through a power supply –included in the package- or through standard Sony NP-F batteries.

As for connectivity, the receiver has two HDMI output jacks and the transmitter one HDMI input and one HDMI output, which could work as a loop for a local monitor.

Inside the box we also found the antennas. They are all the same, which makes fitting easier while preventing errors that could decrease signal range or even damage the devices themselves. Each device makes use of two antennas, and we found in the box that Hollyland has decided to include a spare antenna, for a total of five. A nice touch.

We were surprised when we found that the kit has just one power supply, although with a jack secured by means of a screw lock. Therefore, one of the devices, typically the transmitter, must be fed through batteries. This makes a lot of sense, as it is normally the receiver the one in a fixed position and the transmitter the device that should give us freedom to move. Therefore, it is pointless feeding the transmitter from a wired source.

The two fitting accessories included in the package are useful when placing the transmitter on our camera, most especially when using DSLR systems, through the slot used for fitting the flash.  In order to have a full system, only a couple of HDMI cables –one for each side- and the above-mentioned Sony NP-F battery are required.

Range test

To check the range, two tests were performed: one on an open field and one inside a building. Let us see the outcomes.

Hollyland TM Broadcast Internationao Outdoor Test
Outdoor test


In an open field -outdoors- the system started experiencing signal issues around 100 meters away. However, as soon as we turned our back from the emitting device, the signal was recovered, allowing us to continue the test with a stable signal up to nearly 200 meters with no obstacles. This leads us to the conclusion that the actual transmission range –ensuring no usual objects will interfere with our signal- is around 100 meters, although in controlled environments we could even reach nearly 200 meters as long as a direct sightline is maintained. This is really good for this kind of systems.


In order to test performance within a building, we left the camera with the transmitter inside the studio and moved freely around the corridors in the building. As soon as we closed the door to the studio and we walked about 10 meters away from the walls, the system began to miss the signal; too many obstacles, too big, also. So, if we want to use this kind of systems in indoor –or more demanding- environments, we would rather use other Hollyland systems such as the next one we tried, Cosmo 600.

A small tip on how to streamline range easily, mostly in indoor environments: instead of placing both antennas parallel to each other, place them making a 90º-angle from each other, in both emitter and receiver.  This will allow us to increase range up to 20 meters, twice the figure with parallel antennas but quite far from the 200 meters achieved outdoors.

Image quality and delay

Image quality –provided we are within proper range- is very good. Visually, compression implemented by the system is unnoticeable and it can be used as transmitter for signal recording without compromising quality. The first thing that starts to be missing is audio, as some glitches can be heard. After that, video signal will go as well. We were able to measure a delay of less than half a second -430 milliseconds to be precise-, which is acceptable. As for battery life, we reached 5 hours with a standard Sony battery, so if we use a high-capacity battery, we can reach a full work session with no trouble.

Cosmo 600 Hollyland Kit
Cosmo 600

Cosmo 600

As opposed to its little sibling -Mars 300-, the Cosmo 600 targets the professional market as if offers much more advanced features, in a different price range, of course.

Hollyland has several Cosmo models, based on range: The Cosmo 400, featuring a range of 500 feet -150 meters-; the version we tried, the Cosmo 600, with a range of 200 meters, and the Cosmo 1000+, featuring a maximum range of 1,000 feet or 300 meters.  Even available are versions 1200 and 2000, featuring really impressive ranges of 360 and 600 meters, respectively. Amazing.  But let us focus in the mid-range option, the Cosmo 600.

The first thing worth noting is the product’s packaging. No doubt, the case in which the kit is delivered is designed to be the carrying case throughout its useful life. It is a pelicase-type of package with an inner foamy material to protect all items, which perfectly fit without any gaps, thus preventing them from being hit and damaged during transport.

The transmitter can be fed either through a Lemo power connector or through a standard Sony NP-F battery, as in the previous model.  The receiver, which is somewhat bigger than the transmitter, is also equipped with a Lemo input jack, although in this instance the battery is of V-Lock type. It even has a power output jack for supplying power directly to other pieces of equipment.

This kit comes with various accessories such as the antennas -5 GHZ in this instance, instead of the 2.4 GHz used by Mars 300-, a couple of fitting implements so we can mount the system on our camera or support, and a couple of specific cables featuring appropriate distance and connectors for a more comfortable use.

Each device comes with a small monochrome OLED screen, which makes setting up and monitoring the system something really easy, and also displays signal power, remaining battery or transmission channel used.

The transmitter is equipped with one HDMI and one 3G-SDI input, as well as one SDI output with input in loop for monitoring the signal to be transmitted. The receiver has one HDMI input and two 3G-SDI outputs.

Build is really robust and the device is made 100% of metal, except for the battery support, which is made of plastic. Even the connectors do not protrude from the casing, thus preventing them from easily getting hit or damaged. These details are signs of a careful design for a device intended for professional, demanding environments.

Range test

As we did with its little sibling, we carried out two tests, an outdoor, open-field test and an indoor test within our studios. Let us see the outcomes.

Worth noting is the fact that the system has two types of antennas, the flat standard ones, and mushroom-type antennas that are optimized for indoor environments, as they are more directional. We must say that we did not find performance differences between both.


The outdoor test comfortably met all expectations, even in an environment featuring some obstacles. Finding a place offering 200 meters of direct, straight-line sight was for us very complicated, so we had to allow a certain degree of compromise.

When we reached 200 meters of distance and -as we said above- without direct sightline and with our bodies placed between the equipment items, we only experienced a couple of signal drops, about 90 meters away and when we reached 200 meters. But we think those drops are attributable to external interference rather than to the system itself.

Devices of Hollyland Cosmo 600 system


The indoor test was performed by reversing the procedure used with the Mars 300. The receiver was left in the studio and the camera was moved freely through the outside corridors.  Afterwards, we reviewed the recording in order to check range and quality of the signal.

The system allowed us to move in the same floor around the building, which features metal doors and traditional partitions, so obstacles are many and very powerful.  It is true that in the opposite side of the floor, more than 100 meters away, linkage was not correct, but we can say that between different rooms, the system performed acceptably.

We got thrilled and then performed the same test but on a different floor within the building, upstairs and downstairs. In this instance, not even by using the above-mentioned directional antennas we achieved a correct link. It looks like ceilings and floors in an office building are too much, as it is logical.

Image quality and delay

The Cosmo 600 system is presented as a wireless video transmission system without delay or compression. Additionally, the signal being transmitted is encrypted by means of a 1024-bit AES protocol. Although there are only a few frames of delay in the system, hardly 6-8 frames at most, image quality is identical to a signal conveyed through cable. It is really noticeable that this is not a compression system.

Such delay may be caused by the transmission itself, but let us also keep in mind that there is an encryption system in place, which will surely add some processing time, especially at the receiving side.


Although both systems target markets that are very different from each other, we can say these are quality systems featuring construction and characteristics that make them a very good option.

Mars 300 is a low-budget system with an incredible range outdoors and fabulous image quality, while Cosmo 600 is a professional transmission system, offering advanced features such as 3G-SDI signal, encryption and uncompressed transmission.

A big difference between both is the transmission system, which is at 2.4GHz in the Mars 300 home system and at 5 GHz in the Cosmo 600 professional system. In order to avoid issues it is recommended to review the applicable regulations in each place. 

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