DJI has been on a rampage the past couple of years; capturing ~80% of the consumer/commercial drone industry and pushing several competitors out of the market in the process. However, it seemed as though DJI was uninterested in the FPV Racing Drone market, content to let companies like Eachine, Foxeer, and RunCam rule that domain…until now.
Last week, the FCC reported three filings from DJI; an FPV Air Unit, FPV Remote Controller, and FPV Goggles. The question arose; ‘Is DJI Making a Racing Drone?’ Today, we have an answer.
DJI Digital FPV System
With yesterday’s announcement, DJI has taken a giant leap into the world of FPV and is set to upend the traditional analog FPV video transmitter market. Keep in mind, THIS IS NOT A NEW DRONE, but rather is meant to replace the video and C2 modules in a custom-built FPV drone. The new, DJI Digital FPV System consists of the HD Camera, the DJI Air Unit (a Digital Video Transmitter and integrated flight controller), FPV Goggles, and a Controller. The system will provide HD video up to 4km away and has some neat tricks (like focus mode) to ensure that your image stays sharp in your primary focal areas. The ubiquity of DJI should bring FPV flying to the forefront of the industry and make it accessible to more people.
It’s worth noting though, this isn’t the first time that DJI has released a standalone FPV system. In late 2017, they quietly announced the Ocusync Air Unit, which included a camera as well as an Ocusync Transmitter and Receiver. This system failed to gain real traction in the market for a couple of reasons; the first and most significant issue was the latency of the system.
The Ocusync Air Unit was limited to a 50ms latency which is far too slow to effectively race or perform any acrobatic flight. However, the HDL transmission system in the new FPV setup has reduced that time greatly; to just under 28ms. While this is not breaking any records, it does puts this the DJI Digital FPV in line with popular analog cameras like the Runcam Swift (over a standard 5.8GHz TX) and in doing so makes it a much more compelling offering for all but the most demanding pilots. Digital systems will generally always have a higher latency than their analog counterparts, so one might ask why make the change at all?
However, the HDL transmission system in the new FPV setup has reduced that time greatly; to just under 28ms. While this is not breaking any records, it does puts this the DJI Digital FPV in line with popular analog cameras like the Runcam Swift (over a standard 5.8GHz TX) and in doing so makes it a much more compelling offering for all but the most demanding pilots. Digital systems will generally always have a higher latency than their analog counterparts, so one might ask why make the change at all?
Why is Digital a Big Deal?
Most of the video we consume today is digital. Phones, tablets, computers, Netflix, Amazon Video, Hulu, cable, and even OTA television; all digital. So why is digital FPV a big deal?
The short answer; quality.
If you’re older than 35, you might remember when analog video was the norm. The image was never particularly great (by today’s standards) but was tolerable if you were close to the transmitter or had a really great antenna. If you were far away or only had rabbit ear antennas, you might end up with more static than sitcom.
This began to change in the late ’80s and really took off in the early 2000’s as television and film began to shoot and broadcast in digital format. Our demand for higher quality video and web-based delivery (read, streaming) further pushed the scales toward a digital future. By 2009, all television (in the US) had converted to digital and we were enjoying the HD revolution.
However, in spite of the higher bitrates and improved quality, there were some issues with digital video transmission that made it unsuitable for FPV drone flying. So, in spite of its flaws and lower resolution, analog video has remained the standard for drone racers around the world. What are these issues? I’m glad you asked. The two biggest issues with digital video were latency and range.
Latency is the total time it takes for data to be transferred or the delay involved with transferring data from one node to another. In the case of FPV racing, it is the time it takes for the video to leave the camera and make it to the pilot’s goggles (and the time it takes for the pilot’s commands to get from the controller to the aircraft.) For FPV flyers, low latency is a requirement.
Imagine for a moment, you are driving an F1 race car through the winding streets of Monaco. The car is moving at close to 100mph and the turns require precise steering to make it around while still maintaining your speed. That alone is something which requires an immense amount of skill. Now, imagine that instead of turning immediately when you move the steering wheel, the car waited a half a second to respond. Then, imagine that what you were seeing was always half a second behind reality. How hard would it be to navigate those streets? Not too bad if you were going 5mph, but at 100mph, you’re going to have some real problems.
When flying at 50 mph (a typical speed for an experienced FPV racer), a 100 ms delay can mean your drone will travel about 6 feet before you receive the video, which could mean the difference in you missing an obstacle or hitting it. In a game of inches, like drone racing, milliseconds count.
While digital systems can provide higher quality video; encoding, transmitting, and decoding that video takes time. Latency for DJI’s first-generation Ocusync Air Unit was ~50ms. This may not seem like a lot but it is over twice that of high-end analog camera/TX setups. The new DJI Digital FPV System cuts that almost in half (28ms) which makes this a much stronger option for serious racers and first-time FPV flyers.
The general rule of RF is that as frequencies get lower, three things happen; the bandwidth decreases but the range increases along with the signal’s ability to penetrate obstacles like trees or walls. Lower frequencies, like 2.4GHz or 1.2GHz, have a longer range than 5.8GHz but lower bandwidth which means lower resolution video and a lower frame rate. With analog systems in the 5.8GHz band, you could expect to get around 500m of range.
After that, you will notice a gradual degradation in image quality but can still fly, even when the image isn’t perfectly clear. However, because of the binary nature of digital video, it is usually either on or off. While there are tricks to stream in low bandwidth environments (reduced quality/bitrate, different encryption methods, etc.) once you lose a digital signal, your screen will likely just go black. This is, for obvious reasons, something you do not want happening while you are flying.
So, chalk up a win for analog, right?
Not exactly. Digital video has come a long way over the last decade, and encoding protocols like h264 and h265 (HVEC) along with tiny chipsets capable of decoding that video are making it easier than ever to compress high definition video and make it easier to stream.
The new DJI system claims a 4km range, which is quite impressive given that it is in the 5.8GHz band. To help improve performance at range, they have created tools like Focus Mode. This trick uses the majority of the bandwidth to transmit video in the center of the screen. Much like in the human eye, the area in the main focal area will be prioritized while the outer edges are allowed to be slightly lower resolution.
Is It Worth It?
As you might have guessed, many people in the established FPV segment are voicing concerns about the price of the system and their displeasure with having to activate the module on DJI’s servers.
The average FPV hobbyist enjoys the tinkering required to create a fully functional aircraft and this unit stands to make the hobby a bit more accessible to those outside the traditional circles.
However, DJI’s push into the FPV space has spurred other established players in the game like FatShark, to get on the digital bandwagon. Just one day after DJI’s announcement, FatShark announced their own HD system, the Byte Frost.
Yes, the ~$900 for the full system is expensive, especially if you have some equipment already and don’t need a controller or goggles or if you have 10 quads and need to outfit them all.
However, if you are just getting started in the FPV game and want to go with a name you trust, this is a quick(ish) and easy way to get started.
We want to hear what you think. If you’re already into FPV, are you going to make the shift from FatShark, RunCam, and the traditional FPV setups or do you think DJI is wasting their time?