One of the questions I get asked the most is: "Can you see what the camera sees when you're on the ground?" Of course, for us, seeing what the camera is recording while it's in the air is absolutely vital for getting the best shots - so this issue I'm going to be enlightening you on the super exciting world of video downlinks!
Joking aside, for me this is actually kind of a big deal. If a video downlink is something you're thinking about fitting to your drone then you should know what could work best for you and how much you might be expecting to shell out.
There are two main types of video downlink: AV and HD. Or. In other words, inexpensive and expensive, but read on to find out if it's worth the money.
We've used AV downlinks for the last few years for a couple of reasons really. The main one being that this is just what was on the first hexacopter that I bought to start Fleye.
But as well as this they are very reliable and the best bit is, you can go into most electronic shops and buy the bits you need to solder up a new cable, which is perfect if you get stuck with a broken one.
TRANSMISSION DISTANCE: Up to 500 metres
TRANSMISSION DELAY: Less than 1msec
WEIGHT: 60g Air Unit, 140g Ground Unit
Our main set up revolved around a Kopterworx HDMI converter, which took the HD signal straight out of the camera and into a neat little device which converted it into an AV link. We've always used Immersion RC transmitters, which use very little power to operate and plug straight into the Kopterworx converter.
We also used the Black Pearl monitors which have a built-in receiver with them. Again it was super easy to tune them into the channel and get going with no wiring on the ground, which worked great for us for a while.
We then upgraded our monitors to SWIT monitors. Little did I know what I had been missing out on -1 could see the screen in sunlight! This meant buying a couple of ground receivers.
Sticking with the Immersion RC systems we went with the Uno 5800 receiver - a really nice piece of kit and very good value. The total AV system for us came to a price of about $190 and this set up worked great for us for ages, but then.
We recently approached Amimon to ask if we could try out its Connex system. Just as we were discussing things, the company released the Connex Mini, an HD downlink system designed to fit neatly onto drones and provide a clean HD link back to the ground.
As mentioned before, I had been really happy with the clarity of our AV link to the ground but this just opened up a whole new world! At $1,485 the Connex Mini doesn't come cheap but honestly. I firmly believe it's worth every penny and if you value getting quality images down to the ground, you should go for HD if you can afford to.
Unwrapping the Mini is where the pleasure begins. It arrives in a neat box that's really nicely designed. Open it up and you'll see the air unit - this is the small palm sized box with two little aerial hook ups. Remove this and you'll find the ground unit.
It's a little bigger than the air unit but that's to be expected and it's a similar size to the AV receivers. Then you've got all the antennae and accompanying cables with loads of spares to fit every type of connector.
AV downlinks still provide a perfectly good service, but you really do get what you pay for with an HD set-up.
Fitting the Connex Mini is also super easy. If you've been reading previous issues then you'll know that we use the Freefly Systems Movi M5 to stabilize our cameras. It's a simple case of connecting up the power, screwing on the aerials and attaching them to the Movi, or any other gimbal craft. and then attaching the HDMI mini cable from the Connex Mini to your camera.
When attaching the antennae, for the Connex Mini it was recommended placing them as far away from carbon or metal components as possible, and also the two aerials must be more than two inches apart. I understand this might be hard on a drone made of carbon fibre but don't worry! We zip-tied ours to the tilt bars on the Movi which seems to work pretty well.
With the ground unit it couldn't be easier. You simply attach the aerials onto the top and then plug the provided HDMI cable straight from the ground unit into the back of your monitor. Then all you now need to do is power the unit with anything from a 2- to 6-cell battery. We used the same connection on our AV systems that we used before.
Powering up and it's a simple case of connecting the batteries on each end. I always like to power up the camera last, as this is what you have to do with the AV systems.
You'll see the Connex logo appear on the screen, then it will say "searching for air unit" and a couple of seconds later you'll have a full uncompressed HD image beamed straight to your monitor.
I've always stayed away from an HD downlink because of the cost and also because I was pretty happy with the AV images we were getting. That was until I started using HD.
I was so impressed by the quality of the image; it was so good you could even tell the finest details of focus in the image. It was an amazing revolution for us and our camera operators love it. as do as our clients.
The Connex systems also have an on-screen display option. It's a really cool feature and it's easy to activate or de-activate with the push of a button. The display will show you the current signal strength and the distance from the air unit to the ground unit.
It will also tell you the battery voltage of the air unit's power supply (which also lets us know how the Movi is getting on) and lastly the video resolution. On the larger Connex (not the Mini) it also gives you the option to select a frequency, whereas the Mini will do this automatically.
We have been really impressed with the Connex Mini's range. So far we have tested it up to 420 metres and had a totally solid link which, to be honest, is plenty good enough for us. We rarely push the limits of the 500 metre legal limit as we feel that heading out to those kind of distances often restricts the shot you're able to get anyway.
The good news is. the Connex Mini is available to buy right now so if you're looking, don't hold back. Happy flying!