In this guide we will learn the fundamentals of a FPV system and how everything is put together. This will be a tutorial aimed towards beginners who are just starting to learn about FPV flying.
I remember back in 2013 when I strapped my brand new Fatshark V3’s around my head for the first time, flying a home made 8-inch quad from the perspective of the craft. It was pure joy, and it still is today.
The frame was made out of four hollow aluminum rods that formed a shape similar to a H. I had the newest top-notch Naza-M Lite FC with the GPS module.
In the front I had a fanzy gimbal made for GoPro Hero4!
I had so much fun in the beginning building and flying these strange flying machines.
1: What is FPV?
2: How does FPV work?
3: The coest of a FPV system
4: Main parts of a typical 5 inch build
5: Analog vs Digital
7: 5.8 vs 2.4 Ghz video
8: Drone Laws
9: How to get super-smooth video
What is FPV?
FPV is short for “first person view”.
FPV makes it possible to control a quadcopter, a plane, or anything that moves, from the perspective of the craft with a real-time video stream, usually with a set of goggles. This feels much more immersive compared to just watching your craft from your own perspective – LOS (line of sight) flying.
Like the guy under. This is pretty much every person’s reaction trying FPV for the first time. Pilot in the background.
How does FPV work?
For a FPV system to work we need a few things:
FPV Cam, video transmitter (vtx), video receiver (vrx), a pair of antennas and power.
The picture above is an analog system. DJI’s digital system works very similar. You have an ‘Air Unit’ that you mount in your craft that consist of a camera, transmitter and two antennas. On ground you have DJI’s digital FPV goggles.
|The basics of a FPV system|
|FPV Cam||The camera sends the video signal to the video transmitter. FPV cams are tiny cameras made for as little latency as possible and high dynamic range for rapid change in light conditions.|
|Video Transmitter (vtx)||The video transmitter sends the video signal as radiowaves to your receiver on ground.|
|Video Receiver (rtx)||This part is usually built into the goggles or monitor. Some goggles, like Fatshark's top tier models HDO and HDO2, comes with an empty slot for the video receiver.|
|Antennas||The Vtx and Vrx needs antennas to work properly. These antennas comes in all shapes and forms. More on that later.|
|Power||The entire system obviously needs power. Power can be taken directly from the FC (flight computer) if there is a 5v/9v connection, a BEC (Battery Elimination Circuit) or directly from the battery connection.|
The cost of a FPV system
A FPV system can set you back anything from a hundred to several thousands dollars. A very basic FPV system will cost around hundred dollars, but the costs will quickly add up when you want more high-end stuff.
Lets take the goggles as an example. You can get a pair of cheap box goggles for 30 dollars from Banggood with a built in battery and video receiver. It will get you started.
But, if you want Fatsharks top tier goggles, Fatshark HDO2, it will set you back 500 bucks. That’s only for the goggles. You will still need a video receiver module and antennas for the goggles. Most receiver modules goes for more than 100 bucks and directional antennas like TrueRC x2 goes for 50 bucks.
With that gear you’re already up in 650+ bucks and you haven’t even started on the gear you need in your craft.
Here are some rough estimates on what each parts of the FPV system costs:
- FPV Cam: 10$ – 50$
- Video Transmitters (vtx): 20$ – 60$
- Cheap box goggles: 30$ – 100$
- Goggles: 100$ – 500$
- Top tier goggles with reciver module: 650$+
- Antennas: 10$ – 30$
- High end directional antennas: 50$+
If you go for DJI’s new digital system. Goggles and 2x Air Units, it will set you back around 900 bucks.
Main parts of a typical 5 inch quadcopter
|Frame||A stiff and sturdy structure, usually made of carbonfiber, that holds everything in place and protect the hardware.|
|FC (Flight Computer)||The main brain on the quadcopter that controls everything.|
|ESC (Electronic Speed Controller)||Controls how much power the motors are getting. The ESC is getting its orders from the FC.|
|Motors||Generates lift. Two motors spins CW and CCW.|
|VTX||A video transmitter that sends a video signal down to your video receivers in your goggles or monitor.|
|FPV Cam||A camera that sends a video signal to your VTX|
|OSD (On Screen Display)||Shows information such as battery voltage, mah and signal strength as an overlay above your video feed.|
|DJI Air Unit||A digital FPV Cam and VTX that works very similar to the analog system. However, the digital system is a more closed system and you can't mix up cams, vtx boards and antennas.|
|Propellers||This one you should be able to figure out yourself.|
|Buzzer||A small speaker that is connected to your FC. Will make a lot of noise on your command or when you failsafe.|
Analog VS Digital FPV systems
I’ve been using both analog systems and digital systems for FPV. Up until recently it was not easy to give an easy answer if people asked me if they should go digital or analog.
With recents updates to DJI’s digital FPV system I don’t really see any good reasons anymore to get analog systems.
Here is the reality:
The DJI FPV system is expensive, but if you compare it to the top-tier products of the analog world it’s basically the same price.
If you buy a DJI FPV Experience Combo package it will set you back roughly 900$ – that’s with two Air Units included that you can mount to your crafts.
A good bundle deal with Fatsharks top tier goggles (Fatshark HDO2) will set you back 700$. That’s without FPV cam, video transmitter and antennas for your craft. That will set you back another 100$+ for each craft.
DJI FPV Goggles + 2 Air Units: 900$
Fatshark HDO2 Bundle + 2 analog systems for your craft: 900$
DJI will give you a crystal clear HD video feed with 30ms latency, while the analog system will give you much worse video quality with lots of interference; for the same price tag.
Both system have great range with the right antenna setup.
If you are going for the top tier stuff, go for DJI’s FPV system.
I would actually go so far and say: Flying with the DJI system is like flying FPV for the first time again. The step-up in video quality is absolutely nuts!
OSD stands for “on screen display”. This is basically an overlay with different information in your video feed. Usually your battery voltage, signal strenght and mAh used. More advanced information like return to home arrow, altitude and speed is also possible if you have GPS connected to the FC.
This information feed is generated in your FC (flight controller) and added to your video feed by connecting your FC in between your FPV cam and video transmitter.
Nowadays most FC have built in OSD that you can manipulate with Betaflight. But in the old days that was not normal. If you wanted OSD you had to get an OSD as a separate unit. OSDs was more basic back then and usually just included battery voltage and maybe a timer.
5.8 GHz VS 2.4 GHz
The most common frequency to run your FPV system is 5.8 GHz.
Traditionally, the biggest advantage of 2.4 GHz FPV systems was that you got longer range and higher penetration with your video feed.
Today the 5.8 GHz antennas has become so good that a 5.8 GHz system outruns your battery range on your quadcopter anyways so a 2.4 GHz system in terms of range would be meaningless.
Another downside of 2.4GHz systems is that the antennas are bigger and easier to break.
Drone laws are different in every country, and you need to find out yourself what laws are relevant for your country. Some countries, like Morocco or Venezuela, have banned drones completely.
In my country, Norway, there are basically three main rules for hobby flying:
- Keep a distance of 150 meters from people and private property
- Don’t fly closer than 5km to an airport
- Never fly higher than 150m above the ground
How to get super-smooth video like the “pros”?
Step by step
- Build a well tuned quadcopter
- Use a Gopro Hero6 or Hero8
- Turn of all types of stabilization in-camera
- Stabilize with Reelsteady Go
Check out this in-depth guide on how I stabilize with Reelsteady Go.
How to get started with FPV
Building your first quadcopter (coming)