DJI O3 vs Walksnail Avatar vs HDZero: Which HD FPV System Should You Choose?

Today, we’re diving into a tough question in the FPV world: What’s the best HD FPV video system for you?

Is it DJI, HDzero, or maybe Walksnail Avatar?

You might think I’m leaning towards Walksnail Avatar since I started the fpv drone hobby with their goggles, but nope.

Because the best system varies for everyone, depending on what you need.

In this ultimate guide, I’ll cover everything you need to know about picking the perfect FPV video system. And we’ll be comparing the video and performance of the O3 system side-by-side against the Walksnail Avatar, HD Zero, and original DJI V1 FPV systems.

Let’s dive in!

First, What Exactly is FPV Video System?

All FPV video systems have two main components – a video transmitter (VTX) on the drone that sends video, and video receiver (VRX) built into a headset or goggles that receives the video.

The VTX takes the analog or digital video feed from an FPV camera on the drone and converts it into radio signals that can be transmitted through the air. It broadcasts the video on certain selectable frequencies.

The VRX receives the radio transmission and converts it back into a video signal that can be displayed in your goggles. It needs to be tuned to the same frequency the VTX is broadcasting on.

The type of video signal (analog vs digital), frequencies used, resolution, latency, and other factors differ between the various FPV systems. But they all follow the previously mentioned principles of video transmission.

Digital vs Analog: Which is Best Video System for FPV Pilots ?

Digital FPV transmits the video feed digitally, just like streaming Netflix or YouTube. This allows for HD resolution, better image quality, and less interference. Many hd FPV goggles also offer built-in DVR recording and other handy features.

DJI was the first to release a truly viable digital HD FPV system. You can finally enjoy FPV with an image quality that looks like something out of this century!

However, digital introduces some latency which could be an issue for fpv racers. Many racers prefer analog video systems. This uses an analog video signal like old school TV to transmit the live video feed from the drone camera to the FPV goggles.

But the downside is that analog transmission is prone to interference, static and low image quality. It’s also limited to standard definition resolution.

Overall, digital FPV systems provides a much better pilot experience compared to analog – especially for new pilots looking to get the most out of their FPV adventures.

Want more info? Read our Guide: Digital vs. Analog FPV Goggles: How to Pick?

Overview of the Popular FPV Video Systems

Now, let’s take a closer look at the top three consumer options available today…

1. DJI Digital FPV System

DJI disrupted the hobby in 2020 with the release of their DJI FPV drone combo. It introduced many newcomers to FPV flying thanks to its easy-to-fly nature and stellar HD video feed.

The DJI FPV drone uses DJI’s proprietary O3 digital video transmission system. DJI goggles are also required to view the HD footage.

DJI O3

The just-released second-generation system from DJI.

Key specs include:

• 1080p 100fps transmission to goggles
• 4K 60fps onboard recording
• Larger 1/1.7″ CMOS sensor
• Electronic image stabilization

DJI FPV V1

DJI’s original digital FPV system. Key specs:

• 720p 120fps transmission
• 2.7K 60fps onboard recording
• 1/2.3” CMOS sensor
• No onboard image stabilization

2. HDZero Digital FPV System

The HDZero system was created in 2017 by RDQ as an open source digital FPV alternative. It aims to provide the benefits of HD digital video in a format that integrates with existing hobby grade gear.

The budget-friendly system from HDZero. Key specs:

• 720p 120fps transmission
• Requires external recorder for DVR
• 1/3” CMOS sensor
• Interchangeable camera units

3. Walksnail Avatar Digital FPV System

Walksnail is the digital FPV system created by Fatshark, sometimes referred to as Fat Shark Vista. It’s a proprietary video protocol similar to DJI. Walksnail aims to provide an improved FPV experience while integrating with existing analog goggles.

Key specs:

• 720p 120fps transmission
• 1080p 60fps onboard recording
• 1/3″ CMOS sensor
• No onboard image stabilization

Walksnail Avatar entered the market after DJI and HDZero as a third digital HD option.

Now that we’re familiar with the key specs, let’s take a hands-on look at the hardware.

Hands-On With the Hardware

I’ll start by showing you the brand new DJI O3 air unit up close on the bench, then we can compare it side-by-side with the other systems.

The DJI O3 Air Unit

Starting with the antenna, it uses a very similar design to the DJI V1 air unit antenna. It’s a diversity system with two internal antenna elements. This should provide the transmission benefits of diversity, but since they are enclosed in the same physical antenna housing, there is no spatial diversity.

Looking at the air unit itself, it’s slightly more compact than the V1 unit and pretty similar in size to the Vista. There are no mounting points directly on the O3 air unit, just a plain aluminum housing. You’ll need to use a 3D printed mount or high strength double sided tape to install it.

The O3 has an SD card slot for expanded onboard storage, a USB-C port for firmware updates, a bind button, and status LED. The connector is very similar to the Vista and V1 units, with UART support for Betaflight OSD and SBUS for your radio control.

It is designed to pair with the DJI FPV Remote Controller 2 and either the DJI Goggles V2 or the new DJI Goggles 2.

Okay, now onto the O3 camera unit. This is where DJI has made some big improvements. It uses a much larger image sensor at 1/1.7” compared to 1/2.3” on the V1. The lens and glass are physically larger as well. This should provide significantly improved image quality that we’ll look at in a moment.

The camera uses the same mounting pattern as the V1, but pay close attention to the lens position when installing it. The lens housing is recessed much further back on the O3 camera, so you’ll need to adjust your camera plate to avoid getting it in view.

Side-By-Side Comparison

Now let’s look at the O3 air unit side-by-side with the other digital FPV systems.

In terms of physical footprint, the O3 is very close to the same size as the Vista and Avatar units. It’s slightly thicker than the HD Zero system.

The O3 camera unit is significantly larger than the others due to its bigger lens and sensor.

With the hardware comparisons complete, let’s power them up and compare the image quality and video performance.

FPV Image Quality Comparison

To evaluate the image quality of each system, I first recorded onboard DVR footage at 1080p 60fps. This lets us see the maximum quality produced by each system’s camera and encoder.

Later we’ll look at the live feed through the goggles to see if transmission degrades the image at all.

Onboard DVR Footage

First up is the onboard recording comparison, check it out:

I won’t tell you which system is which just yet. Look closely at the level of detail, sharpness, and color in the frames. Which do you think provides the ideal balance of vibrant color while still retaining fine details?

Now here are those same clips zoomed in 200% so you can closely examine the finer details:

Being able to make out branches, leaves, and other small features is critical for precisely navigating through gaps and around objects. Based on these zoomed clips, which system do you think captures foliage detail the best?

Alright, now that you’ve gotten a feel for the onboard recorded footage, let’s see how they compare when transmitted live to the goggles.

FPV Feed Through Goggles

Here are zoomed clips showing the live feed through each system’s digital goggles:

The image you see here represents what you’d see while actually flying. Look for any degradation in quality compared to the onboard recordings. Is the foliage still as sharp? How well can you make out small details?

And now here are the full unzoomed feeds:

With the systems unmasked, which stands out to you as having the highest overall video quality? Share your picks down in the comments!

Low Light Comparison

Let’s change up the conditions and see how the systems compare in low evening light:

And here is a true night flight with almost no ambient light:

When it comes to low light and night flying, which system do you think handled it the best? The worst? Again, let me know your thoughts in the comments!

Now that you’ve seen the systems back-to-back in multiple conditions, here is my full analysis and breakdown of the video quality showdown.

Video Quality Analysis

Starting with the HD Zero system, I found it delivered the least detailed image of the four. However, it seemed to handle low light conditions remarkably well, revealing details in the twilight and night clips that other systems struggled with.

The DJI V1 and Walksnail Avatar systems were very closely matched for me. The V1 footage is slightly more sharpened while the Avatar has a softer look, but both captured similar levels of fine detail. The Avatar may resolve a bit more in certain shots like foliage and trees.

When it comes to low light, I feel the V1 still beats out the Avatar by recovering more shadow details. Although the Avatar’s default exposure could probably be tuned to improve this.

But the clear winner in terms of outright detail is the brand new O3 system. The 1080p feed really makes a difference, allowing far more resolution to be transmitted compared to the 720p systems. And the new H.265 encoding does an incredible job retaining all that fine detail even at 50mbps.

The large 1/1.7” sensor gives it a tremendous advantage when it comes to resolving the tiny elements that allow you to fly precisely. Check out how clearly you can see the details of the trees in the O3 footage.

However, the low light performance doesn’t quite measure up to the V1 or HD Zero systems. The large sensor size should provide an advantage there so hopefully DJI can improve it with future firmware updates.

The highly saturated color and contrast of the O3 is gorgeous for video but harder to fly with. I’ll take the flatter look of the V1 or Avatar feeds any day for actually piloting and staying oriented.

So in summary, if outright detail and resolution are your top priorities, the O3 delivers in spades. But that comes at the expense of low light handling and a more saturated image.

Now let’s move on to the equally important metric of latency.

FPV System Latency Comparison

To accurately measure and compare the end-to-end latency of each system, I set up a 1000fps high speed camera to capture the video feed in the goggles as well as an LED on the drone.

This allowed me to precisely measure the milliseconds between the LED illuminating on the quad and that change appearing in the goggles feed.

Let’s check out the results:

The HD Zero system clearly has the lowest latency at just over 30ms. The DJI V1 and Avatar systems are very close behind at 34ms.

The O3 comes in the slowest at around 40ms when recording in 1080p 100fps. However, latency gets significantly higher if you drop the O3’s recording frame rate down to 50 or 60fps for 4K video.

So what’s my takeaway here?

Latency Comparison

Obviously DJI chose to prioritize maximum image quality and resolution with the O3 system at the cost of latency. Pushing all those extra pixels introduces processing overhead that adds delay.

40ms is still very flyable for most pilots as long as you’re not racing or doing hardcore freestyle. But personally I’d take the snappier 34ms feel of the V1 or Avatar anytime.

The bigger issue is the recording frame rate dependence. If you want sharper 4K video at 60fps, your goggle latency jumps up over 60ms on the O3 which is starting to get noticeable.

So you have to pick between the fastest feed for piloting, or slower frame rates for cinematic footage. That’s a frustrating tradeoff caused by the processing overhead.

For pure low latency performance right now, the HD Zero is king. But the V1 and Avatar are so close that I doubt any pilot could truly feel the 1-2ms difference.

Now let’s move on to one of the most hyped features of the new O3 system: 4K 60fps onboard recording with image stabilization.

O3 Onboard Recording Quality

Here are some clips showcasing the O3’s onboard recording capabilities:

First up is 4K 60fps without stabilization so you can see how well it performs handheld:

Even with some handshake from manual flying, the detail is impressive. The large sensor really captures a high level of fidelity.

Now here is stabilized 4K 60fps footage using DJI’s “RockSteady” electronic image stabilization:

The footage is amazingly smooth and stable without affecting the clarity. This would be incredibly difficult to achieve manually with such clear footage.

Having onboard stabilization makes getting cinematic flying shots as easy as hitting record!

So in summary, the onboard recording abilities of the O3 system are simply in another league beyond any other dedicated FPV system thanks to the 4K resolution, bitrate, and stabilization.

It gets remarkably close to the quality you’d get from a premium action camera like a GoPro. Stay tuned to the blog as I’ll be doing a full comparison against GoPro and other action cams very soon!

Who Should Choose the DJI O3 FPV System?

Now for the big question: who is the O3 system best suited for? Here are my thoughts and recommendations:

Cruise and Cinematic Fliers

If you enjoy a more relaxed, scenic style of freestyle flying and want the highest quality FPV feed, the O3 is tough to beat. The 1080p resolution and sharp detail immerse you in the environment. Plus you get pro-level 4K onboard footage.

The latency is very manageable for casual flying. Just don’t expect to set any race records with the O3!

Video Content Creators

For FPV pilots focusing on capturing cinematic aerial video for YouTube, Instagram, or other outlets, the O3’s stabilized 4K60 recording and excellent dynamic range help you create stunning videos with ease.

You have the flexibility to use ND filters, adjust exposure settings, and manipulate motion blur to get exactly the shot you’re looking for in post with high resolution footage.

New FPV Pilots

Because it’s a DJI product, the O3 system is easy to set up and start flying quickly. The goggles integrate OSD and DVR recording seamlessly. So it’s a great all-in-one solution to get in the air fast if you’re new to the hobby.

As your skills progress, the O3 video quality leaves room to grow without needing to upgrade anytime soon.

Who Should Choose Another System?

While the O3 will be the ideal system for some pilots, for others, it may not be the best fit:

FPV Racers

If you’re racing or setting lap times, every millisecond counts. The additional latency of the O3 system will put you at a disadvantage against pilots with lower latency set ups.

Stick with the V1, Avatar, HD Zero or analog for the absolute lowest latency when racing is the priority.

Raw Freestylers

For hardcore freestyle pilots who push the limits flying full throttle through tight gaps and around objects, latency is your enemy too. The O3 video simply can’t match the snappiness of the other digital systems that top out around 34ms.

Again, the V1, Avatar, or HD Zero will provide the lowest latency for raw freestyle.

DVR-Less Systems

One advantage of the HD Zero system is you can interchange camera units. This means you could use a Caddx Vista unit for digital video, and a different action camera like the GoPro Hero 10 for onboard recording.

That modular capability comes at the cost of not having integrated DVR though. So it depends on your priorities.

Final Thoughts

DJI has clearly achieved their goal of creating the highest quality integrated FPV video system available today with the O3. The 1080p feed and 4K recording check every box for resolution and clarity.

But that comes with some tradeoffs, namely latency that will rule it out for some pilots. Fortunately there are great options like the Walksnail Avatar and HD Zero that cost far less while providing lower latency.

I don’t think the O3 is inherently a better or worse system overall. It’s just optimized for different priorities compared to the other options on the market. As always, choosing the right digital FPV system depends entirely on matching the performance to your preferences and style of flying.

I hope this complete DJI O3 review and shootout versus the other major systems helped point you in the right direction! Let me know which system you’re leaning towards and why down in the comments.

And be sure to subscribe so you don’t miss my upcoming full comparison between the DJI O3 onboard recording quality versus dedicated action cameras like the GoPro Hero 10 and Runcam 5.

Happy flying!