It’s freaking 2024 guys – analog is on the way out the door. I’m sorry, that’s just the truth. The days of analog have been numbered ever since, by my count, 2019, when DJI released the DJI FPV system. That was the day that analog started declining.
You can still find people out there who listen to music on vinyl, but most people listen to MP3s and streaming services. That’s just how it is, and these days you can still find a lot of people who fly analog FPV, but those numbers are declining.
Sorry if that hurts to hear, analog pilots, but I’m here for the facts, not your feelings! If you don’t like it, that’s just how it is. So that makes me wonder – why in the world has Skyzone released the Sky04X Pro? The Sky04X is a fantastic analog goggle, one of the best. And this new version is basically just that same goggle, but with something added to make it more compatible with digital FPV.
Oh, I see – a really, really good analog FPV goggle with the capability to support digital FPV as well. Well, I guess that makes some sense.
Whenever I review a product like the Skyzone Sky04X Pro which is based on a previous product I’ve already reviewed, it’s tempting to just say “Yeah, you saw my old review right? You know what this product is…” and then basically skip over it. But that’s not fair, because this new version isn’t just the same old product repackaged for 2024. And many people haven’t seen my old review and deserve for me to look at this product with fresh eyes.
But for those of you who are familiar with the Skyzone Sky04X as an analog goggle, here’s what you need to know – the Sky04X Pro is basically just the Sky04X, but now updated to support digital input via the HDMI port.
Skyzone goggles have always had an HDMI input – you could plug them into your laptop or computer and use them for a simulator, or even just as a display. But they haven’t been ideal for use with modern digital FPV systems – until now.
The idea is that you can take something like the Walksnail standalone video receiver, which has an HDMI output. You plug the Walksnail receiver HDMI into the Sky04X Pro HDMI input. Now you’ve got a janky, but functional way to use Walksnail digital FPV without buying their goggles. And that’s the promise of the Sky04X Pro.
But does it actually deliver on that promise? Well, there’s at least one way I already know it falls short if you’re using HDZero (but more on that later). First, let’s start from the beginning and review the Sky04X Pro from the ground up.
Table Of Contents
Overview
The first thing you’ve got to know about the Sky04X Pro is that these are first and foremost analog FPV goggles. They come with Skyzone’s own analog receiver module. This means they can receive signals from analog FPV video transmitters and cameras.
What does analog mean? It means the image quality is going to be like television in the 80s or 90s, before we went digital and HD. Less resolution, scan lines, etc. The image breakup will also have that static-y, analog look.
We’ll take them out and fly to test the Skyzone receiver’s performance. Historically their receivers have been decent, but not the absolute best analog modules you can buy.
In the past, Skyzone FPV goggles supported “diversity” – where you’d have two receiver antennas, and even a second receiver module on the other side of the goggle with two more antennas. That is no longer the case, and I’m kind of okay with that. Diversity only improved reception in certain limited cases, and almost no one actually used the second module.
The reason diversity is gone is that the new screens in the Sky04X Pro are higher resolution and larger, which generates more heat. So a fan has been added to help keep things cool.
The screens are now 1920×1080 full 1080p resolution. That means they are also 16:9 widescreen ratio. The older Sky04X was 1280×960, not only lower resolution but also 4:3 aspect ratio.
Many people feel that 4:3 is better for analog goggles, because old-school analog video was 4:3, before widescreen formats existed. Most analog cameras still have 4:3 sensors and lenses designed for it. When you display a 4:3 image on a widescreen 1280×960 display, you get letterboxing. The 4:3 image is shown in the center, with black bars on the top and bottom.
This wastes some of the resolution, although 1080p is still way more than you need for analog SD video. However you feel about it, the screens on the Sky04X Pro are now 1920×1080 widescreen.
Not only are the new screens higher resolution and widescreen, they are also larger. Instead of a 46° field of view, the Sky04X Pro has a 50° FOV. Whether you’re viewing 4:3 or 16:9 video, the image will be significantly larger and more immersive.
The final change to the screens is that the new OLED panels support a higher refresh rate. This is to support modern digital FPV systems that can do up to 120 FPS for lower latency. We’ll test whether the Sky04X Pro can actually make use of these higher frame rates later in the review.
Features and Controls
Let’s quickly run through the various ports and controls on the goggles:
- Power Input – accepts 6S max, so you can use any of your flight batteries. Comes with an XT60 to barrel jack cable.
- Head Tracker Output – if you use a head tracking system, it’s supported.
- USB Port – can be used to power the goggles from a USB power bank, or update firmware
- HDMI Input – for digital video input
- Micro SD Card Slot – for recording DVR, and maybe firmware updates
- AV In – for attaching an external analog receiver, though most will use the built-in one
- Headphone Jack – for analog video transmitters that also have audio channels
There’s also the standard adjustable IPD and diopters for focusing the displays. According to the manual, diopter adjustment is from -2 to +6, and IPD from 58mm to 71mm. Pretty standard range for most FPV goggles.
One of the hardest things to get right with goggles is ensuring a comfortable fit for different face shapes. Skyzone cleverly includes two different foam faceplates in the box. One is rounded and narrow, the other wider and flatter. You can test which fits your face better.
I also can’t help but notice the incredible amount of cooling and anti-fog vents included on the Sky04X Pro. Check out these little air ducts that will blow air across the lenses. There’s clearly been a lot of thought put into keeping these lens fog-free!
Analogue Performance
Since the main feature of the Sky04X Pro is compatibility with Walksnail’s high FPS digital modes, I’ve set up a test to confirm it can support them.
I’ve got the Walksnail Goggles connected via HDMI to the Skyzone goggles. I could have also used the Walksnail standalone receiver, but I already had the Goggles bound to my quads.
I’ll cycle through the different video modes on the Walksnail side, and point a GoPro into the Skyzone goggles so you can see the results. Keep in mind you’re looking at a GoPro inside the goggles, not seeing the actual image quality yourself. But the results should still be clear.
First, standard 720p 60fps video. No problem, the Skyzones handle this basic mode fine.
Switching now to Walksnail’s 720p 100fps high frame rate mode. Again, no issues – the Skyzone is able to display and keep up with the 100fps signal. Though I did have to re-plug the HDMI cable once to get it to sync up correctly.
Now we’ll try 1080p 60fps. Once again, no problem for the Skyzones.
Walksnail recently added 1080p 100fps high frame rate support. But the Skyzones don’t seem able to display this format at all. No matter what I tried, they wouldn’t work with 1080p 100fps.
This doesn’t really surprise me. I believe all these goggle manufacturers buy the same displays from Sony or other suppliers. The 1080p 100fps mode might be pushing the limits of what the OLED panel supports. Walksnail might not care about the long-term risks, but Skyzone has chosen to play it safe.
Finally, we’ll try Walksnail’s “Racing Mode” which is 540p resolution at 100fps. This non-standard resolution is only meant for FPV goggles. Amazingly, it does work perfectly on the Skyzones. I’m impressed, since 540p100fps is not a video mode you’ll find on any normal display device.
The Sky04X Pro was clearly designed with Walksnail compatibility in mind. I did notice the image looked over-exposed and had an odd color temperature compared to the Walksnail Goggles. But that could probably be adjusted in the display settings.
Image Quality Concerns
Speaking of image quality, I have to mention one disappointing issue with my review unit. There are two large pieces of dust or debris visible in the right side optic. They are inside the lens, not something I could clean off externally.
You can tell because the specks move in and out of focus as you adjust the focus wheel. This is clearly a defect introduced during manufacturing. To fix it would require opening up the goggles and cleaning the inside of the optics.
I would expect Skyzone to exchange the unit for any customer with this issue. Their support is usually pretty good. But it’s disappointing to see in a review unit, and makes me wonder about Skyzone’s quality control. Hopefully this is just an aberration and not a widespread issue. Image quality is too important to ignore defects like this.
Fit and Comfort
Before taking the Sky04X Pro goggles out flying, I wanted to test the fit and comfort. This is one of the most personal and subjective aspects of any FPV goggles. But Skyzone has historically had some of the most comfortable goggles on the market.
For me, the Sky04X Pro fit perfectly. There were no pressure points on my nose, brow, or temples. It felt evenly distributed across my face. No light leaks either, except for a tiny gap near the upper vents.
The fit won’t be the same for everyone of course. But at least for my face, the Sky04X Pro felt like they were custom made for me. Way more comfortable than most other boxes I’ve tried.
One downside of the ultra-large 50° FOV is that if the goggles are not aligned perfectly, the corners will be cut off due to the circular optics. I could see the effect when trying to view my OSD in the bottom left corner. A 50° FOV feels almost too immersive – I think I’d prefer 46° for the best mix of immersion and being able to see the whole uncropped image.
FPV Flight Test
To really evaluate FPV goggles, I have to take them out for some test flights. Even with the minor concerns I’ve mentioned, my first impressions of the Sky04X Pro are very positive. But will that impression hold up in the real world? There’s only one way to find out!
For antennas, I’ll be using these aftermarket upgrades rather than the stock rubber ducky antennas the goggles come with. The stock antennas are linear polarized, which is not ideal. Every pilot should be using circularly polarized antennas, both on their goggles and video transmitter. So considering the antenna upgrade cost when comparing goggles is fair in my opinion.
Alright, the quad is in the air and… wow, the image looks great. No breakup at all here close to home. The Unify Pro video transmitter in the quad is solid, so that’s expected. Let’s try flying behind the house to see if it starts breaking up.
Still not too much breakup, even with the house blocking direct line of sight. The receiver is holding together well, with just brief static but no rolling, flashing, or other artifacts. Very nice!
Okay, time to really stress test the range. I’m going to face my antenna away from the quad to intentionally cause breakup. Even with the signal this weak, we just get some brief static. No rolling or other issues. The Skyzone receiver seems solid.
If I drop down lower behind the trees… yeah the image gets pretty staticy. But it’s staying stable and watchable even with very poor conditions. This module is performing about as good as I could expect for an analog receiver. No complaints from me!
Value for Money
It’s tempting in a review to skip talking about price. Pricing changes too rapidly in FPV to keep a video up to date. But goggles pricing is pretty competitive these days, so I think it’s worth discussing value for money.
Refurbished DJI FPV Goggles V2 can be found for around $300 USD. The Fatshark Dominator goggles for Walksnail are $380 new. So there are options out there for getting into digital FPV pretty cheaply.
The Sky04X Pro sells for $600. Compared to the $459 Walksnail Goggles, they’re about $140 more expensive. The Walksnails will obviously work better with Walksnail digital FPV than these will. But they’re also terrible analog goggles, unlike the Sky04X Pro.
Compared to the HDZero goggles which also sell for $600, the Skyzone bundle includes an analog module while HDZero does not. But the Skyzones don’t include an HDZero module. So if you wanted to use both analog and HDZero, the price for either goggle would end up similar after buying modules.
Value depends on what you’re looking for. If you want Walksnail digital, but also care about analog performance, the Sky04X Pro makes sense despite the higher price. The HDZero would be better optimized for HDZero, but can’t do Walksnail digital input at all.
So if you’re an analog first pilot who wants the option to dip your toes into digital, the Sky04X Pro hits a nice sweet spot despite being a bit pricier than the other options.
Final Thoughts
The Skyzone Sky04X Pro takes an already excellent analog goggle and makes it cross-compatible with leading digital FPV systems via the HDMI input. While not the cheapest option, it’s a logical choice for people who fly both analog and digital.
There are some concerns, like the image quality issues I noticed. And digital systems like HDZero won’t get the full benefits of the 100FPS display when using the HDMI input method. But those are tradeoffs some people will happily make for the flexibility of a great hybrid analog/digital solution.
For anyone who flies mostly analog and wants to experiment with digital without fully committing, the Sky04X Pro is a great choice. It will give you 95% of the digital experience, while being a top-notch analog goggle simultaneously.
That flexibility comes at a price premium over more focused options like the Walksnail Goggles or HDZero FPV System. But for people who aren’t ready to give up analog completely, the extra cost brings significant advantages. The Skyzone Sky04X Pro hits a nice sweet spot between old and new technology, appealing to pilots who still have one foot in each world.
