HOLLYLAND MARS 400S PRODigital Wireless Video Transmission System

Built by Hollyland and costing around £600 the Mars 400S is an easy-to-use wireless video transmitter/receiver system – it will be right up the alley of anyone who, like me, considers an instruction manual to be nothing more than box padding.

The body is made of metal as opposed to plastic, which gives it a sturdy, professional feel. It’s compact, although not the smallest model on the market with the receiver and transmitter each weighing half a pound (206g), which obviously adds a little bit of bulk when shooting freehand.

While they look the same, the transmitter and receiver are clearly labelled and different coloured rings by the hot shoe, red for transmitter, blue for receiver, make identification of each element easy. The only plastic elements are the four detachable antennas, which have solid screw in SMA connectors, so can be easily replaced if they break – and a spare is included in the box, very helpful.

Both parts can be powered by either an NPF battery or via lock-in DC power and you can swap from battery to plug power without picture loss. It would have been good to have two DC chargers included to enable power to both the transmitter and the receiver at the same time but a plus point is that the same battery type is required for both elements, unlike some transmission systems which require different batteries for the transmitter and receiver.

Each item features an easy-to-read OLED panel, which flags up all the information you need really, such as the channel to which you are connected (up to eight channel options), the signal strength and a simple ‘video’ or ‘no video’ indicator to indicate that a video feed is coming through and whether the internal fan is switched on or off or set to auto. The battery power level is indicated by a volts reading, an unusual but beneficial feature that gives a more accurate picture of how much power there is left, as opposed to a bar indicator.

There are both SDI and HDMI input and outputs on the sender and receiver respectively and those options make it a more professional option compared to some models on the market. There’s also a USB-C port, which another nice feature as it enables direct connectivity to a computer for live-streaming. In my test the transmitter ran for just over 10 hours from a fully charged NPF mid-sized battery.

It transmits up to 1080P at up to 60 frames per second and in my test it could be picked up at a distance of 350ft, but through a wall – the product specs say it will transmit from 400ft with no obstacles in between. I was pretty impressed with the quality of the signal and the range. It was very reliable in my test with one momentary drop out as I approached the range limit.

Unfortunately it doesn’t come with a pass through option, so it’s not possible to add a monitor to the camera and then go from that via the transmitter to the receiver – the transmitter has to connect directly to the camera for it to work.

One aspect I was impressed with was the free ‘Hollyview’ mobile app, which connects up via an internal wifi network. It worked well and the app comes packed with all the useful picture assist features such as zebras, waveform monitors, focus assist, histograms, safe zones, magnification options, false colours and you can even layer on a 3D lut. The transmitter can send a signal to up to four devices or two if used in conjunction with the receiver. I really think this is a great tool to have at your disposal on set.

The latency is 0.8 of a second and so any major time delay comes from the monitor as opposed to a major delay between the transmitter and receiver.

All in all, I think this is a good solid and by my tests very reliable piece of kit. While if looks and feels a little chunky, its neatly put together and gives a reassuring air of professionalism.