FPV is quickly becoming one of the most popular and unique sport all over the world. It gives every ordinary person the chance to be able to fly like a bird, and for me it’s just the most surreal and addictive experience.
In this article, we are going to look into what FPV is for multicopters, how FPV system is setup from basic to advance, how to choose hardware for FPV, and finally lots of useful tips and information around FPV.
- What is FPV
- How Does FPV work
- FPV Camera
- Video Transmitter / Receiver
- FPV Antenna
- FPV Goggles / Monitor
- Voltage Regulator
- Power Filter
- FPV Tips and FAQ
What is FPV
FPV stands for First Person View. In RC hobby, FPV generally refers to the way an unmanned vehicle or aircraft being controlled by the pilot through an onboard camera. The real-time video stream enables the remote pilot to fly the multicopter (or drone if you prefer), without looking at it line of sight (LOS). Therefore FPV is sometimes called video piloting as well.
Some fellow FPV flyers would compare it to playing computer games. It’s kind of like that, only difference is if you are flying some $300 equipment in the air, which you spent days putting together. The level of focus makes this hobby real intense and sensational. FPV suits almost everyone, whether you are into fast racing style, or relaxing aerial filming, you will find yourself hooked.
Benefit of FPV
Apart from the addictiveness, there are advantages in flying FPV.
FPV flying is a more precise way of controlling your multicopter thanks to the first person perspective, especially if the environment is full of obstacles which might block your line of sight views. Therefore the quadcopter is able to fly at higher altitude and further distances.
It also makes the experience far more realistic for the remote operator, allowing them to better feel for the environment and more optimally navigate their crafts. To Summarize:
- More agile flying
- More precise control
- Fly further and higher
- More fun!
Cheap FPV Options
I strongly recommend building your own multicopter and setting up your FPV system, and this is what this article focus on. But if you don’t have the electrical skills or time, there are also other cheap ‘plug and play’ FPV quadcopter options available. One famous example would be the Hubsan H107D FPV Mini Quadcopter.
This is a complete FPV system, the LCD screen and video receiver are built into the radio transmitter. It’s a relatively cheap way to get you into FPV flying, and a pretty good training platform.
How Does FPV Work
UAV Technology continues to advance, all aspects of the drone flying hobby just keep on growing and improving: reliability, safety, user experience, features, options and so on. “GPS Return to Home”, “Head Tracking FPV System”, “3D FPV Goggles”, “Object avoidance”, “Follow Me Feature”, You name it!
But back to the subject on FPV and how it works, the most basic FPV system consists of
- a camera
- a video transmitter (VTX)
- a video receiver (VRX)
- a video display device.
The camera is mounted on front of the multicopter, which gives the pilot the feeling of being on the aircraft.
The live video is transmitted wirelessly on the video transmitter, and picked up by the video receiver on the ground. Video is then displayed either on a monitor or FPV Goggles.
More sophisticated setup may include GPS and all sorts of sensors, to provide comprehensive flight data on the screen using some On Screen Display device, OSD.
Here we will go into more detail about each component in the FPV system.
FPV cameras are generally light and small so they can be fitted on a small unmanned aircraft. Just like choosing any other cameras, first thing to look at would be the resolution. But apart from that there are also other important factors in making the decision.
Check out this comprehensive guide on selecting a decent FPV camera. As a summary here are the factors that you need to consider.
TVL – Resolution
TVL is the camera resolution measurement.
600TVL is kind of the standard now, and it’s good enough for most people and display devices. You can always fly with a lower TV Line camera such as a 380TVL, but the image is not as clear as a 600TVL camera. There are now 800TVL even 1200TVL, which is apparantly better for larger screens and higher resolution FPV goggles.
Camera Type – CCD or CMOS
CCD and CMOS are two different imaging sensors in cameras. CCD is a bit more expensive than CMOS camera, but better for FPV due to the following reasons:
- Less jello
- Better light sensitivity
- Greater dynamic range
- Less noise
GoPro, Mobius, Runcam HD are all CMOS camera, and not the best camera for FPV in my opinion (Good for HD recording though). Although they all have video out, but the dynamic range and latency isn’t very good. For a more detail explanation why you shouldn’t use GoPro or Mobius for FPV, check out this post.
Video Output – NTSC / PAL
It really isn’t a big issue whether to use PAL or NTSC nowadays, as they are both supported by most FPV equipment.
The main different is that PAL offers better resolution, while NTSC allows more frame rate. So if you want to have good picture, PAL is good. But if you want more fluid footage, NTSC does a better job.
PAL: 720 x 576 @ 25fps
NTSC: 720 x 480 @ 30fps
Latency in FPV camera is important, especially to those who fly proximity and racing. With delay in video feed will result in slow pilot response. Dedicated FPV board cameras are generally much better in terms of video lag, compared to those HD recording camera such as GoPro or Mobius.
However this is not something the seller would indicate on their products, so before making a purchase make sure you find out about this attribute from other users’ reviews.
Video Transmitter and Receiver
Video Transmission is the heart of FPV system. It determines how reliable your video link is and how far you can fly without video cutting out.
Before going into specific products, you need to first understand the frequency these video transmitters and receivers operate on.
The common frequency used in FPV are:
- 900 Mhz
- 1.2 ghz
- 1.3 ghz
- 2.4 ghz
- 5.8 ghz
Here is a guide on FPV frequency, explains what the advantages are with each frequency.
Basically the lower frequency has better penetration ability, but they have huge antenna. Note that not all frequency are legal for FPV in every country, check your local regulations before deciding.
The most popular frequency right now is probably 5.8Ghz because:
- Legal in most countries
- Small antenna
- Widely available
- little to none interference with 2.4Ghz radio
Each frequency has a number of channels. for example the 5.8Ghz has 32 channels. It gives the pilots the choice to choose different channels when flying together, so they don’t knock each other’s video out.
Not all video transmitter / receiver can run on all channels, it’s brand dependant. Make sure your VRX matches your VTX.
Video Transmitter Power
You will see video transmitters rated at 25mW or 200mW or 600mW or even 1000mW (1W). The larger the power, the greater the range. But you can’t just blindly choose one with huge power.
First, you need to check if it’s legal to run that FPV frequency at the given power in your country (region).
Secondly, the increase of range is very ineffective with increase in transmitter power. To double your range, the power has to increase 4 times in theory. Let’s say if a 200mW VTX gives you 1Km range, to get 2Km, your transmitter power has to be 800mW at least.
I personally find it unnecessary to go extreme on frequency and power. Many people runs 5.8Ghz 250mW on their mini quad and getting more than 1Km range (with some good antenna). Most people don’t even fly that far out normally anyway. However 5.8Ghz is not so good when there is obstacles in between the pilot and the multicopter, such as trees or buildings.
Antenna for VTX and VRX
When it comes to Antenna for your video transmitter and receiver, there are a few concepts you need to familiarize yourself with first.
- Antenna Polarization: Circular or Linear
- Antenna Gain: Directional or Onmi
Although VTX and VRX come with stock antenna, they are not the best when it comes to range and can be affected by interference easily. They are what we call Linear Polarized antenna. It’s recommended to get circular polarized antenna for your FPV system for optimized performance. Check out this tutorial on why circular polarization is better.
Directional antenna has even further range, but you have to point your antenna towards the multicopter at all time (bad signal when your copter is on the far left/right or behind you). For more detail, here is a guide on how antenna gain affects range in FPV.
Types of Antenna
There are many types of antenna used in FPV, I will list the most popular and common types of antenna.
- Onmi Directional Antenna – This include the stock whip antenna that comes with your VTX or VRX. They have equal range from any direction, and they are very easy and cheap to make.
- Cloverleaf and Skew-Planar Wheel – These are circular polarized antenna usually with a small gain. When you look at the 3D range diagram, it appears to be a doughnut shape, less range above and below the antenna, but further range all around it horizontally.
- Helical and Patch – These are directional antenna, that has better range and penetration. This post explains in detail what Helical and patch antenna are.
Antenna Connector Type – SMA and RP-SMA
When choosing antennas for video transmitter and receiver, make sure the type of connectors are compatible. Check out this post for the SMA / RP-SMA differences.
FPV Goggles / Monitors
Many people get stuck when choosing FPV goggles or monitors. FPV goggles are way more expensive than a monitor, that’s why when I started, I was using a cheap LCD 7′ monitor that lasted a year before I upgraded to a proper FPV goggles.
I really enjoyed flying with my monitor, I could switch between flying Line of sight (looking at the multicopter), and FPV easily, especially useful for landings. But I enjoy flying with a pair of FPV goggles even more, as I am able to see things more clearly, and feels more in control. Also a pair of goggles is easy to carry around, the battery last a lot longer than the monitor, and isn’t affected by sun light at all.
Apart from price, it’s also a personal preference. Some people enjoy the immersive flying experience with FPV goggles, but some might find it causing headache, or feeling uncomfortable wearing them. Also eye conditions could affect your usage of goggles.
If you are interested in goggles, it’s best to borrow a pair from your friends, and try it on before making the decision. Check out this FPV Goggles comparison for more technical information.
Tips for shopping Monitors
If you decided to go for a monitor, I think there are a few things you should look at:
- Correct video Input: make sure the monitor supports AV input, that works with your video receiver.
- Input Voltage: make sure the monitor can be powered by 2S or 3S LiPo.
- Features: some comes with built-in VRX, DVR, they are no necessary but would be useful.
- Size: I think 7 inch monitor is pretty good for FPV, it’s not too bulky to carry either. Of course larger monitor gives you better image detail.
- Brightness and Backlight: important if you are expecting to fly under the sun. Although you could use a sun shield, it won’t block the light completely and you will still have trouble seeing the screen if it’s not bright enough.
- Blue Screen: When losing video signal, some monitors just turn blue screen (or black). This is considered not suitable for FPV, what you want is a screen that shows static when signal is gone. That’s because sometimes you might still be able to make up a vague image from it which lets you to turn back or do your stuff.
OSD – On Screen Display
An OSD is used to overlay flight information about your multicopter into your FPV live video. This is totally optional, but having flight data like battery voltage, GPS information, speed, altitude and so on would be extremely useful.
For example on all my quadcopters, I have an OSD to report at least the battery voltage level, so I know when I should land.
Here is a complete OSD guide for beginners.
Input Voltage and Voltage Regulators
You need to make sure your FPV equipment is powered by appropriate voltage. Most FPV equipment input voltage are rated for 12V these days. If you are powering your quadcopter with 3S LiPo (11.1V), you can also power your FPV systems directly with your main battery.
However if you are running 4S LiPo or more, you can power your FPV gear with a separate 3S LiPo, or you can use something called ‘Voltage Regulator’, to step down voltage (from 4S 16.4V to 12V for example).
LC Filter (Power Filter)
Motors generate a lot of noise in your power system. If you are powering your FPV gear with same battery, the noise could get into your video transmitter and camera, which results in jumping white lines across the footage. It’s especially obvious when you throttle up.
LC filter (aka power filter) is used to reduce noise in power supply. They can be bought ready made, or you can DIY your own power filter.
FPV Tips and FAQ
If you are running multiple cameras on your quadcopter, say a FPV camera and a GoPro, you might consider using a video switcher, so you can switch between these camera on your FPV goggles or monitor by using a switch on your radio transmitter.
It’s especially useful for those who are flying with their FPV camera, but also want to occassionally check what you are filming with the HD camera.
Video frequency conversion!
Some FPV goggle has built-in VRX that only support 5.8ghz, if you want to run 1.3Ghz or 2.4Ghz, you can make a box that connect up 1.3Ghz VRX to 5.8Ghz VTX for conversion.
Can I use my iPad, smart phone or other tablets for FPV?
You certainly can! You can either send your live video via wifi, or use anologue to digital video converter to display the footage on your mobile device.
However I don’t recommend doing do, the delay will be so bad you will crash your multcopter.
Where to put my FPV components on the model?
Generally speaking, place your VTX antenna as far away from other antenna as possible, e.g. your RX antenna, your GPS antenna.
What is Jello I hear about everywhere?
Jello is the effect where vibration gets into the camera from maybe your motors, propellers, or simply badly tuned quadcopter.
You might not observe jello when flying FPV, but horrified how much vibrations you have in your recorded HD footage. This is because it affects CMOS type cameras more than CCD camera due to how camera shutter works.
What to do with FPV camera audio?
If you are not using it, simply ignore it, or cut the wire off.
How to learn flying FPV?
Someone asked me what the best way is to learn flying FPV. Some might assume they have to become really good at LOS (flying line of sight), before they start FPV. Personally I find LOS and FPV two very different ways of flying. Once you master the basic control with LOS, you can move on to FPV if you want.
Also Quadcopter Simulators really help beginners pick up the basic skills quickly, and reduces the cost of broken parts due to silly errors. Here are a list of RC Multicopter simulators.
Hopefully this article has helped clear up some of the basis of FPV flying. Do your research, ask questions, make sure you understand it before buying.
Feel free to joinour facebook group: www.facebook.com/groups/Copter.Fans/.