Wireless video transmission used to be extremely expensive. It still can be if you need higher-end kit, but it’s started to come down to much more reasonable prices. One such reasonably priced wireless video transmission is the Hollyland Mars 400S which comes in at only $649 and supports both HDMI and SDI inputs and outputs. I’ve been using the Mars 400S for a few weeks now, and have found it to be quite useful in situations where I wouldn’t normally be able to stand right next the camera to monitor what it sees while it’s recording. Is it the right system for you? Well, keep reading, and you’ll be able to make that decision for yourself.
The whirlwind tour
The Hollyland Mars 400S comes as a transmitter and receiver pair, which look fairly simple and straightforward. They have a metal body construction with an OLED display on the front, with three buttons for sifting through the menu system.
On one side there are HDMI and SDI ports. The transmitter has HDMI and SDI inputs and the receiver has HDMI and SDI outputs, and while I haven’t been able to test it myself, I reached out to Hollyland to find out if you can switch from one signal type to the other. Hollyland assured me that you can use an HDMI camera in the transmitter with an SDI monitor on the receiver, or going the other way with an SDI camera plugged into the transmitter and an HDMI monitor on the receiver.
Above the video ports is a Type-C USB socket for upgrading the firmware of either unit. On the other side are a DC power input socket which takes between 6-16v DC, and an on/off power switch.
On the top are a pair of standard male SMA antenna sockets for screwing on female SMA antennas. Even though only four antennas are needed (two per device), Hollyland actually includes five of them in the box so that you have a spare in case you lose or break one.
On the back of each unit is a socket for a Sony NP-F style L series battery. I typically use the NP-F550 style batteries with these to keep them lightweight, although they will handle the NP-F970s just fine, too. And the battery lasts quite a long time on these. Even with the NP-F550, I’ve yet to have it run out during a day’s shoot. The DC input means you can also power it from an external power source, too, like perhaps the DC output of your on-camera monitor, if it has one.
Also included in the box is a bracket to help with mounting the transmitter to your camera rig, along with an AC adapter, and a Type-C USB to Type-A converter.
The menus and basic operation
The menu system is pretty standard between both units, which allow you to change various settings. The receiver has one very handy feature, though, which is a channel scan. This way, you can find the cleanest signal to minimise any interference. I typically shoot in fairly low noise areas, so for me, all channels look usually good. But any high traffic frequencies will have an X next to them, suggesting that you should not try to use them.
While only one receiver is included in the kit, the Mars 400S transmitter actually can support two of them simultaneously. This can be handy if you want to stream it out to a couple of people at the same time, perhaps a focus puller and a director. Extra receivers are available to buy separately. To wire it up, you simply take an HDMI or SDI cable from your video device and plug it into the transmitter. Then you use another cable to plug the receiver into your monitor. If you need to monitor locally on a monitor, too, you’ll want to make sure you’ve got one with HDMI passthrough, so that you can go from the camera into the on-camera monitor, and then out from the monitor into the transmitter.
Establishing a connection is pretty simple, too. Simply power up both units and the receiver will look for a transmitter with an active signal and connect to it. If you’re in an area with a lot of interference, you might want to do the channel scan I mentioned earlier in order to find a suitable channel. Then set this on the transmitter and the receiver should be able to find it – although you can manually set the channel on the receiver, too, if you wish.
It also supports streaming to up to four mobile devices, too, although your mileage may vary with a smartphone connection. To connect from your mobile device, you scan a QR code on the back of the transmitter. I had no problem connecting and streaming to my ASUS ZenFone four, but when I tested it with a OnePlus 7 Pro, it wouldn’t even acknowledge that it had seen a QR code on the transmitter. This is likely something that can be fixed in a future firmware update. Once you do get your smartphone to connect, though, you’re able to use various camera assist features including waveform, histogram, focus peaking and various others. It even has 3D LUT support.
You’re also able to grab a frame of the transmission and draw on it and make notes. You can also record video clips straight to your mobile device – perhaps useful if you want to grab a quick something to post to social media.
As I have several field monitors and a whole stack of NP-F style batteries with which to power them, I tend to stick with just using the Mars 400S receiver rather than my phone. In all my tests at home, to see what it could handle, it did very well. It was able to take a 1366×768 resolution output from a laptop and transmit it to a 4K TV. It was able to transmit from a Raspberry Pi to the HDMI input on my desktop monitor. I’ve even tested it with my Blu-Ray player, watching on one of my Feelworld monitors. But one of the most useful tests I did was to have a camera transmitting to a capture device on my laptop. Specifically, the Elgato Cam Link 4K.
This can be very useful if you’re live streaming, allowing you to place your camera pretty much anywhere without having to trail wires all over the place. There is a cooling fan inside both the transmitter and receiver, though, so you’ll want to be careful with your microphone placement (although the fans aren’t very loud).
Taking it outdoors
Out on location is where such a device is most useful, thanks to the massive 400ft range Hollyland lists in the specs. In reality, at least where I went to shoot, I managed to get much more than that. I had no problem up to 400ft at all and still manage to get a strong signal up to a pretty crazy 650ft or so. I wanted to take it out into the Scottish wilderness to try to minimise the amount of external influence and interference there might be on the system so as to get as clean a signal as possible. I already had a shoot scheduled for that day, so it seemed like a good idea to take it along. I had an HDMI cable going from my camera to the Feelworld F6 Plus monitor mounted on top, and then the HDMI output from the monitor went into the Mars 400S transmitter. The receiver was plugged into the Feelworld FW279, also using HDMI, and the overall setup worked rather well. You can see the full range test in the video up top, but I was actually still getting some signal around 700ft, although it wasn’t quite as reliable. By the time I got to around 725ft, it cut out completely. This is way above and beyond Hollyland’s stated 400ft, so unless you’re in an area which is getting a lot of interference on all channels, or you’re blasting your signal through a lot of thick walls and floors indoors, it should hold up to many real-world shooting scenarios. I used the system throughout the day, and it never let me down while recording. The transmitter and receiver paired up every time I turned the units on and there were no glitching or other issues of any kind, really. One thing that concerned me when I first saw the units was the on/off sliding power switch on the side of the units, but in reality, these turned out to be amazing. They switch smoothly and lock into place solidly at both the on and off positions. They’re also easy to switch on and off even when you’re wearing gloves in the freezing cold Scottish weather. I’m not too keen on the little bracket that comes with the Mars 400S kit, though. It doesn’t feel very secure when mounted to the transmitter and either a camera’s hotshoe or a cold shoe on my camera cage.
To be fair, the bracket itself is fine, it’s the metal cold shoe adapter that screws into it. The thread locks are small and fiddly, and they’re metal, too, which means that they don’t really bite down very well on whatever you’re sliding the foot into.
This made me feel a little uneasy sometimes when walking around with the camera handheld and limited my mounting options. When the rig was on the back seat of the car as we were driving around, it did actually slide out a couple of times. I think the solution here is to find a more substantial cold shoe adapter to screw into either the bracket or the base of the transmitter. Something like the SmallRig 2346 field monitor mount, which has holes on the thread locking screw, into which you can insert an Allen key to really lock it down.
Overall, though, it was a fantastic system to work with, especially as I had to spend much of my time in front of the camera that day on location, and not just behind it. Having the transmitter allowed me to have a monitor close by to check focus and composition, even though the camera itself was a good 5 or 6 metres away from me. It also meant that as we were clambering over the terrain, I could have a monitor to keep an eye on the shot of my friends behind me. I’d know exactly when everybody had walked out of the camera’s view, we’d got the shot and it was safe to walk back into frame to go back and stop the camera.
Pros
I’ve tried a few low (and very low) budget video transmission options over the years but none have been as reliable as the Hollyland Mars 400S. Many of them have given a loss of signal at a fairly short distance, or they’ve seen constant interference, quality loss or a lot of glitches in the feed. At $649, I think the only other system out there that might offer better bang for the buck is the slightly cheaper HDMI-only version of this device, the Hollyland Mars 400.
A strong solid connection at insane distances, well above the 400ft advertised in a clean outdoor location with no interference.Smooth video at a high quality, with the option to optimise for speed in high air traffic locations.Solid metal construction.An OLED display that’s easy to read in the day, showing all the useful information.Channel scanner to check for interference and find the strongest signal channel.Cast to a mobile device (when it works).A DC power input socket so you’re not forced to carry extra batteries if you don’t need to.Removable antennas, so that if you lose them or they break, replacements are readily available.
Including an extra 5th antenna in the box so that you have a spare handy already definitely gets it some bonus points, too.
Cons
There isn’t much to dislike about this system, although it’s not perfect.
The cold shoe adapter is terrible. If you buy the Mars 400S, get yourself a better one.Not all mobile devices seem to be able to connect easily, not recognising the QR code on the back of the transmitter.
The latter of those will likely be solved in a future app update, and a replacement cold shoe isn’t a massive extra expense. It’ll also come in handy for mounting other things, too, like the on-camera monitors for which it was intended, or perhaps a small LED light or microphone mount.
Final Thoughts
The Hollyland Mars 400S is a very nice system. There are less expensive video transmission systems out there, but none that are as reliable, in my experience. Sure, there are higher-end systems out there, offering more range, higher resolution, and all the bells and whistles, but you’re going to be paying significantly more money to acquire one. The Mars 400S sets the bar, really, for a low-cost high-quality video transmission system offering both HDMI and SDI. If you know you’ll never need SDI, you can save a little money by going with the HDMI-only version, the Mars 400, which also offers HDMI passthrough on the transmitter, and a pair of HDMI outputs on the receiver. I’ve waited for years for HDMI video transmission systems to offer this level of quality at this price point. It’s not a capability I ever really felt I needed enough before to justify prices in the thousands. But now that I’ve had a few weeks with wireless video transmission as part of my workflow, I’m not sure I can live without having this option available to me when shooting. And the Hollyland Mars 400S fits the bill perfectly. The Hollyland Mars 400S is available to buy now for $649 and includes the transmitter, a single receiver, five antennas, the mounting bracket, cold shoe adapter, Type-C to Type-A USB adapter (never did figure out the point of that), and a quick start guide.
