FPV Guide for Multirotors | First Person View System

FPV allows the pilot to control and fly their drones from ground, seeing the world from the perspective of a bird. 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 Flying

FPV stands for First Person View. In RC hobby, FPV generally refers to the way an unmanned vehicle or drone being controlled by the pilot through an onboard camera. The real-time video stream enables the pilot to fly the multirotors (or drone) remotely, as if the pilot is sitting on the aircraft.

Traditionally in RC hobby, the pilot normally controls the aircraft by looking at the it line of sight (LOS). But in FPV the pilot sees what the drone is seeing, and so it’s sometimes called video piloting as well.

Some would compare FPV flying to playing video games. It’s kind of true but only you don’t want to smash your expensive drone into the ground like you do in a game. The level of focus required makes the experience really intense and sensational. And only because of FPV, drone racing (mini quad FPV) is possible.

Benefits of FPV

Apart from the addictiveness, there are some real advantages in FPV to flying RC models.

FPV flying can be 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 view. Therefore the quadcopter is able to fly at higher altitude and further distances in FPV.

It also makes the experience far more engaging for the remote operator, allowing them to see the environment better and easier to navigate. To Summarize:

  • More agile flying
  • More precise control
  • Fly further and higher
  • More fun!

How Does FPV System Work

FPV systems are actually very simple. Sure there are a lot of product options with different spec and features, but the connections  are more or less the same. A basic FPV system includes these core components:

FPV Camera => Video Transmitter (VTX)=> Video Receiver (VRX) => FPV Goggles or Monitor

fpv-system-setup-basic-explain-diagram

The camera is mounted on the front of a quadcopter, so the pilot can see what the quad sees.

Live footage is then sent wirelessly from the video transmitter, and picked up by a video receiver on the ground. And finally the video is displayed either on a monitor or FPV Goggles.

More advanced and sophisticated setup may include telemetry, OSD, DVR and other gear. Here we will go into more detail about each component in the FPV system.

FPV Camera

FPV cameras are generally light and small so they can be fitted on a small unmanned aircraft. But they do not have the best video quality compared to HD footage you see on youtube. That’s because they are analog cameras designed for extremely low latency yet provides the best possible wide dynamic range for FPV.

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 FPV camera.

 

Video Transmitter and Receiver

Video Transmission is the blood of a FPV system. It determines how reliable your video link is and how far you can fly without video cutting out.

The basics of Video transmitter for quadcopters.

There are some concepts you need to learn first:

Not all video transmitter / receiver can run on all channels, it’s brand dependent. Make sure your VRX matches your VTX.

Antenna for VTX and VRX

Learn about FPV antenna basics and how to choose the best FPV antenna in this tutorial. In this guide we covered:

  • The Pro’s and Con’s of Linear and circular polarized antennas
  • The differences between Omni-directional and directional antennas
  • The types of FPV antennas
  • Antenna Connector types

VTX and VRX normally come with linear polarized antennas, however they are not the best for multirotors and can be affected by interference more easily. 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 for quadcopters.

Directional antenna allows further range in the expense of narrower angle of reception. You have to point the directional antenna towards the multicopter at all time for the best signal, signal quality degrades when the copter is on the far left/right side or behind you). For more detail, here is a guide on how antenna gain affects range in FPV.

FPV Goggles / Monitors

FPV goggles are more expensive than a monitor, but FPV goggles provides a much better flying experience.

Check out this FPV Goggles comparison for more technical information.

There are some advantages to flying FPV with a monitor apart from cost. It allows the pilot to easily switch between flying Line of sight (looking at the multicopter), and FPV. Monitor also makes it more convenient for those who wear glasses.

7-LCD-Monitor-Screen-fpv-stand

However it cannot beat the experience with flying with a pair of FPV goggles: image is much more clearer, does not get affected by sun light, and they are generally more compact for transportation.

FatShark-Dominator-HD-goggle

Apart from price, it’s also a personal preference. Some people enjoy the immersive flying experience with FPV goggles, but some might get a headache from it, 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.

FPV Monitor – What to Consider

If you decide to go for a monitor, there are a few things that you should look at:

  • Correct video Input: make sure the monitor supports AV input that is compatible with your video receiver
  • Input Voltage: make sure the monitor can be powered by 2S or 3S LiPo, or any other power source of your choice
  • Features: some comes with built-in VRX or even DVR. They are no necessary but would be useful
  • Size: I think 7 inch monitor is the minimum screen size for FPV, any smaller it becomes difficult to see clearly
  • Brightness and Backlight: it’s important to be able to adjust brightness, if it comes with a backlight that would even be better. When flying under the sun you could use a sun shield, but it won’t block the light completely and you will still have trouble seeing the screen if the monitor isn’t bright enough
  • Blue Screen: When losing video signal, some monitors just turn blue screen (or black). This is considered unsuitable for FPV, because when you’re on the edge of losing signal the picture will simply go blank. What you want is a screen that shows static when signal is weak. 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. You could perhaps add a DVR to “fix” the blue screen issue

Fresnel Zone

To ensure you have the best possible signal your VTX antenna should be in the line of sight view of the VRX antenna at all time.

When you fly behind a tree, or a hill, your signal will weaken or even drop completely as you are outside of the Fresnel Zone. When this happens you might have video breakup or static on the screen. The problem becomes more obvious in higher transmission frequency. That’s why your radio signal (2.4GHz) normally have longer/more reliable range than your video (5.8GHz)

Remember that since most mini quad frames are made of carbon fibre, it’s important to extend your antennas long enough to avoid being blocked by the frame or other electronics components such as your HD camera.

Diversity Receiver

A Diversity receiver allows multiple antennas to be used at the same time, and it will always switch to the antenna with the strongest signal.

When combining omni antennas with directional antennas, you can get the best of both worlds.

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.

MINIM-OSD minimosd-kv-mod-connection-naze32-d4r-ii-rx-fpv-camera-vtx-setup

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.

voltage-regulator

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-power-filter1 lc-filter-circuit

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

Video Switcher

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.

fpv-video-switcher

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. Although all you could hear is the sound of motors, some people actually prefer flying FPV with audio.

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.

That’s all

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.

18 thoughts on “FPV Guide for Multirotors | First Person View System

  1. David

    I’m finding the hardest thing about FPV is orientation and I think it has something to do with the choice of lens on the FPV cam. I use a board ccd cam from a security cam. I have no idea what kind but, the picture is good and it handles light changes well. The picture doesn’t look anything like the picture of cam footage I commonly see on youtube and I can’t help thinking it’s because of the lens. I have no idea what the field of view or size specs of the lens are either. What lens should I be trying? I maybe should buy one of the popular sizes i.e. 2.8, 2.6, 3.6 and see or what? I have one of those all in one cam/tx from spectrum that seems the best overall as far as being able to tell where I am in the world but, don’t like it as a package for a race quad. Maybe if I soldered on an antennae extension cable to relocate the antennae or something. I don’t know I’m just rambling but, I think what I’m trying to say is it’d be great if more attention to lens choice were given in your otherwise fantastic FPV tutorial.

    Reply
  2. Kam Zadeh

    PLEASE HELP! Can I directly connect a small FPV camera to my Samsung Note 4 smartphone via OTG cable and USB cable by soldering FPV’s 4 wires to a USB port and bypassing RC wires, transmitters, receivers …? Is this at all possible and how?

    Reply
  3. Scott

    Wonderful site, thank you so much
    Could you please say more about the compatibility and advantages of different video antenna types.
    I imagine you have some great insights into techniques to avoid RF interference such as separation, placement, avoiding ground loops, using twisted pairs, filtering, and shielding for each type of signal or device, ie raw video feeds, servo leads, GPS antennas, ESCs, analog sensor signals, etc
    I’m especialy interested in using coax for servo and raw video signals, as I understand the shielding should be grounded only on the cleaner end so should not be used as ground for power.
    Is it true that while a twisted pair of power wires will reduce the emf given off by the wires it does nothing to protect from interference unless of course they are also shielded?
    Although populer ethernet cable can be a dangerous choice to power all but the smallest servo, it just to thin, and using multiple strands together should also be avoided to avoid loops, it does work well for signal wires using only one of each pair with the other tied to the shielding again at the clean end only since there is no differential signaling like used with ethernet (not needed for our realitivly short if noisy cable runs).
    For serial, I2C, CAN, and others, ethernet cable would also be a good choice, also using only one of each pair for each signal
    Of course only use finely stranded and shielded cat6.
    Shielded USB cable has larger power wires that can safely power a servo, though only one of the few that I cut up has much shielding between the power and signal wires.

    I have used thin satalite reciver coax for servo signal without issue, and would like to do the same for the raw video or would somthing bigger be better?
    Must the EMI shielded GPS stands be grounded to be effective?
    Any thoughts, corections to my thinking, or general advice would be greatly appreciated
    Keep that wonderful content flowing

    Reply
  4. paz

    “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.”

    Do you mean that fpv systems that use mobile-phones/pads are ‘all’ bad?

    Reply
  5. Joshua

    Hi Oscar, Very helpful for an FPV beginner!
    BTW, apparantly should be apparently @ TVL – Resolution section :)

    Reply
  6. Chad

    Oscar, As many others have said before, your blog is awesome. The thing I appreciate most is HOW it is written. So many manuals jump right into specific details without giving a general overview first. This method often leaves huge gaps in your UNDERSTANDING about a subject. Your links allow the reader to expand outward into the “spider web” that keeps growing. A simple “thank you” is not enough. Now on to my matter at hand.

    I have read and understand individual components and narrowed the field a great deal as far as I can tell. I am at the “compatibility” stage. For example, will a Dragon Rider DRAK TX (buddyrc.com/dragon-rider-5-8g-40-channel-adjustable-fpv-av-transmitter.html) work with any comparable RX such as Immersion RX’s? It would seem that the specs are right but there may be other issues which will degrade the overall performance. It seems it would be best to use as many devices from the same manufacturer as possible as they SHOULD have been tested as a SYSTEM. But in this case, I can see how the flexibility of the DRAK might be an advantage later.

    I have a list of components prepared for an FPV (thanks to your help) that I can provide.

    Reply
  7. sam

    ” You can either send your live video via wifi, or use anologue to digital video converter to display the footage on your mobile device.”

    Hi thanks for all the tutorials.

    Can you please elaborate more on how to get live video to smartphone. And if there is any lag you suggested any ideas on how dji does it without much lag??

    Im planing to build 5.8GHZ fpv for my RC car, which i drive withing 20 m radious , do you think i can still see the video sitting in my room, while driving it outside my house.

    thanks

    Reply
    1. Oscar Post author

      haha, it’s the same font used on facebook, which is read by more than 1 billion people in the world… this is the first complain i ever heard that has difficulty reading it…

      Reply
  8. Wilco

    Hi Oscar, Thank you for taking the time and effort to write the guide and all the other fantastic content on the site. Please keep it up. It’s highly appreciated!

    Reply
  9. Dj_Garfield

    Hi Oscar :)

    Allways the best of Multirotor Guide !!!
    You allways know how to talk about this Hobby , and make scientist syntax understandable for all People :)

    You become the must-have reference !!!

    Reply
  10. Sebastian

    Hi Oscar,

    respect to the effort you put into this hobby fible! I’m pretty long into this hobby, but still I’m learing when I read your blog entrys. This is such a good ressource. Thanks again for you efforts and keep it up ;-)

    Regards

    Sebastian

    Reply
  11. eephyne

    Very nice article, it’s always a pleasure to read them.

    For monitors you just forgot to talk about white noise/blue screen, which is really important when buying (even if it’s not notified everywhere…)

    Reply

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