Review of the new ZWO ASIAir Plus

I was invited to review the all-new ZWO ASIAir Plus, the latest generation of the ASIAir device aimed at simplifying the image acquisition process of astrophotography. Let's take a look at this exciting new device...


The ASIAir Plus is the third generation device of the extremely popular ASIAir platform. The ASIAir consists of two components to simplify the process of image acquisition for astrophotography, the hardware and the software app.

The Software: The ASIAir mobile app is constantly being updated and new features are being added all the time. ZWO seems to try to do their best in making the app features backwards compatible with the earlier hardware versions, but occasionally new features come out that are just too hardware intensive to be able to run on the older units with lower / slower specifications. As of this writing, the app for the ASIAir Plus does not differ at all from the ASIAir Plus aside from the addition of the eMMC section that was added to support the new internal storage of the Plus.

As not much is different between the software for the ASIAir Pro and the ASIAir Plus, let's take a look at the new hardware.


ASIAir Plus


Why Would I Need an ASIAir Plus?

The aim of the ASIAir products are to replace your laptop with all it's image acquisition software and equipment drivers. This small portable device replaces the need for a laptop sitting next to  your telescope for the entire night. Who wants to expose their expensive laptops to the elements anyways?

No need for a bunch of cables dangling from the telescope/mount down to the laptop perched nearby. The ASIAir Plus has a finder shoe mount which allows it to be easily mounted to your telescope where you can wire it to all your cameras, dew heaters, mounts, and accessories with short lengths of cable that have no chance of getting snagged on your mount. You only have to worry about the single power cable coming from the ASIAir — or, alternatively, the Pegasus Power Box that I have in my setup that powers the ASIAir.

As far as software, you don't need N.I.N.A, APT, or other image acquisition software to manage the session. The ASIAir app handles image capture plans, auto-guiding, auto-focus (with the EAF), filter changes (with the EAW), slewing the mount to the target, etc. No need to update or install all those ASCOM drivers...everything is self-contained. When the ASIAir app updates via the app store for your mobile device (phone or tablet), the next time you power up the ASIAir and connect with the app, your ASIAir will update the firmware on the device.

Portability is the name of the game with the ASIAir. Everything is built into this little device and it's software. It's light enough to go on a small star tracker for your portable rigs to travel out into the field. It doesn't require internet access (aside from the initial activation of the unit which you can do from home). No need to bring your laptop and cables, all you need to run the unit is a mobile phone or tablet, which gives the freedom of mobility away from being tethered to the scope and laptop — you can watch and control your session from the warmth of your sleeping bag or car.

However, the ASIAir is not just for those on the go. I use mine in my own backyard for easy image acquisition. The ASIAir can connect to my home WiFi network for complete control from anywhere in my house. Aside from being outside to do the initial polar alignment, I can keep an eye on my guiding and image session inside and from the coziness of my couch. When it's time for bed, I don't have to stay up and babysit my session. The ASIAir will take care of doing an automatic meridian flip, switch targets, autofocus, and all while I get some ZZZ's. No more staying up all night watching your imaging session and going to work groggy. When my image session is over, the ASIAir turns off my camera cooling and returns the mount to the home position. In the morning I just put the lens caps on my cameras and download all my images wirelessly to my computer via the WiFi connection (alternatively you can use the MicroSD or USB thumb drive to transfer the files).

Essentially the ASIAir revolutionizes the process of image acquisition with total portability and ease-of-use. There are some other products on the market that offer similar features: PrimeLuce Eagle, StellarMate, AstroBerry, etc., but I don't believe any of them offer the affordability and accessibility that the ASIAir has managed.


ASIAir Plus box

Contents of box


What's in the Box?

Included in the box:

  • ASIAir Plus hardware unit with external WiFi antenna
  • ASIAir Quick Start guide
  • ASIAir Activation guide
  • 2x DC male-to-male power cables (1m)
  • 2x DC male-to-male power cables (0.5m)
  • 1x DC male-to-female extension cable (1.5m)
  • 1x USB 3.0 Type-B Data Cable (0.75m)

What's NOT included?

This is just a caveat to anyone that might be purchasing the ASIAir, which I have noticed a lot of people don't realize, is that it does not come with a power supply. I imagine it has to do with lower cost and internationally different power standards. This is just a warning if you want to hit the ground running when you order an ASIAir, make sure you buy a power supply as well. You can get one from ZWO here.


ASIAir Plus vs. ASIAir Pro

The ASIAir Plus is the newest generation of the ASIAir. So you may already have a ASIAir Pro, or you might see the ASIAir Pro on sale everywhere right now and wonder why you should consider an upgrade or purchase the cheaper Pro. Well let's take a look at the new features of the ASIAir Plus:


ASIAir Plus Antenna


External WiFi Antenna

This is the big one. If you don't already have an ASIAir and are in the market for one, this is the top-selling feature of why you would want a Plus over the Pro. It is a well-known fact that the WiFi on the Pro is abysmal. Taking a couple steps away from your mounted ASIAir would be enough to drop the connection at times.

Nearly everyone that has purchased an ASIAir Pro, has then gone on to purchase another device to extend the WiFi reach of the Pro. This could be done with mobile routers, WiFi extenders, Wireless Mesh units, etc. For a time, ZWO even sold a Vonets WiFi antenna to extend the range of the Pro.

So if you're a first-time purchaser, it's likely that any amount of money you're saving on an ASIAir Pro discount, you're going to lose by having to buy an additional WiFi extending device. If you already have the ASIAir Pro and the means to extend the WiFi, then this is likely not a huge selling point, though it is nice to shave off the extra weight and connections from your rig.


eMMC Internal Storage

With the ASIAir Pro, your options were to store images on either a MicroSD card or an USB thumb drive. With the ASIAir Plus, another option has been added. The eMMC internal storage provides 20GB of extra internal storage that is quite faster than the other storage options (ZWO states that it's 2.5x faster than the Pro).

One big extra feature of this new storage is that it now contains the ASIAir OS (opposed to it being stored on the MicroSD card on the Pro). With the OS on the MicroSD, there was the chance that the card would get corrupted (especially if you were taking the card out and transferring files to your PC), which would then cause your ASIAir Pro not to work. It was common practice to always backup the MicroSD card image or have a backup card as a precaution.

Additionally, with the Plus, the system can rollback to a previous version of the firmware if it should become corrupted. This could be a life-saver if you were out in the field or just didn't want to waste any more precious clear skies if the OS gets corrupted.


ASIAir Plus power outputs


Power Outputs

The hardware here hasn't changed for the Plus, they still output the same amount of power and there are still 4 outputs, but they have added LED indicators denoting which outputs are active (you can turn off outputs you aren't using through the app). In addition to the power indicators, the app will now show the voltage and power consumption which could be quite handy in determining power requirements or battery runtime.


Side-by-side Comparison Plus vs. Pro


Smaller, Slimmer, Faster

The ASIAir Plus dimensions are 100mm x 70mm x 26.5mm, making it 24% slimmer and 17% lighter than the ASIAir Pro. While it's not drastically different, smaller and lighter is always better when you have a product being designed for portability. You can see the differences between the two in the images above. You would probably notice that I have velcro on the top of my Pro which is how I attached the TPLink travel router that was required to give the Pro decent WiFi capabilities. Being able to ditch the router should also be taken into consideration in addition to the device's lighter & smaller form factor.


Inputs and Outputs

The ASIAir Plus and Pro have the same ethernet port as well as the same USB-A ports (2x USB 2.0 & 2x USB 3.0). It should be noted however that the USB 2.0 and USB 3.0 ports have switched around between the two models. No big deal, but something to note when connecting your devices.

One change that ZWO has made to the Plus is the addition of a USB-C port. This is not something I would generally use because I transfer my image files wirelessly, but this allows the connection to a laptop/PC to transfer the files.

It would have been neat if the port was more functional to support additional storage or devices, but as it stands it can only be used for transferring files.


ASIAir Plus mounted to telescope


My Final Thoughts

I think the ASIAir Plus is a fantastic device. It makes automating your image acquisition process simpler and more portable. I would definitely recommend anyone who has a portable rig to immediately purchase the ASIAir Plus. If you have a backyard rig and want to pare down your complicated setup consisting of a laptop being subjected to the elements, or want to get away from managing a bunch of drivers and updates, definitely consider getting the ASIAir Plus.


What about people who already have a ASIAir Pro?

Before I was considered for the early review process, I had already put in my order for the first run of the ASIAir Plus. I have a need for an additional unit for another rig and loved the features that they added to the third generation unit so there wasn't even a debate. But if I had an Pro and didn't see the use for having a second unit, there would be some things I would consider. 

First, the WiFi antenna. I can definitively say that the ASIAir Plus with the WiFi antenna performs better than my ASIAir Pro with the TP-Link AC750 travel router. This was the go-to router when people were having issues with their range on the ASIAir Pro. I mainly have the ASIAir Plus connected to my home network in station mode, but I have tested the range of the Plus with just the antenna and it reached further than the Pro + the router. I was able to connect to the ASIAir Plus from my living room where I wouldn't even be able to see the network with the ASIAir Pro + router. I attribute this extra range to the antenna vs the router which had no antenna. So it's possible that people with the Vonets antenna extender or similar extenders would get about the same reach.

Secondly, the internal eMMC storage is a sizable benefit to the Plus over the Pro. Removable storage is prone to damage to the ports or getting corrupted, so internal storage is always beneficial. I also like the security of knowing if there is a corruption of the OS, it can do a rollback to a previous firmware version. That adds peace of mind that you won't have to waste precious clear skies. Theoretically, with the faster I/O speeds of this internal storage, the whole system should run faster. I did notice the app felt faster when responding to my input when on the Plus, though I don't have the metrics to measure that. Also, my auto-guiding seemed marginally better with the Plus, which I attribute to the faster OS. It is known that PHD2 performs better on faster devices so I believe this is the cause of the slightly improved guiding.

Additionally, the onboard storage means you can free up an USB slot if you were previously using the USB thumb drive for storage on the Pro.

Ultimately you'll have to decide if the upgrade is worth it based on these factors, but for me it was a win.


What about devices similar to the ASIAir Plus?

I don't have a lot of first-hand experience with some of ASIAir's competitors so I can't weigh in on that directly, but I can provide some observations and knowledge about them. 

NUC / Mini PC - Having a NUC or Mini PC certainly overlaps some of the benefits of the ASIAir as far as portability goes, but this is not much different than using a laptop when it comes to the software. You still need to run all the same software and manage the drivers and updates. There's also the additional work of networking to a remote PC to control your session.

Astroberry - Another Pi based system, but you need to setup and do EVERYTHING yourself. This is an option for experienced users only. No where near the ease-of-use of the ASIAir.

PrimeLuce Eagle - I don't have personal experience with the PrimeLuce Eagle devices, but they look very capable and a good competitor to the ASIAir. The difference here though is that the Eagle devices are a premium device at a premium cost.

StellarMate - This is probably the closest competitor to the ZWO ASIAir Plus. The price points are very similar as well as the functionality. Again I don't have experience with this device, but if you want to compare two similar devices, this is likely the one. The big difference with Stellarmate is that it is open source and therefore supports a lot more devices, though possibly a bit more difficult to use due to that. But that brings me to my last point...


What if I don't have ZWO devices?

I think this is the one downfall of this product. The ASIAir devices do not support other brand devices (aside from mounts and DSLR cameras). So you will not be able to use astrocams, filter wheels, auto focusers, auto rotators, etc. that are not ZWO brand.

If you already have a bunch of equipment from other manufacturers, the ASIAir is likely not for you and you may have better luck with the Stellarmate if you are looking for something similar.


The Downside

Aside from a few features missing from their software, which I'm confident will eventually make their way to the app, I only wish ZWO opened up the ASIAir so that you could use other equipment you might already own.

Due to being locked into the ZWO ecosystem, there is one glaring hole in the line of automation products that you have to accept: ZWO has no automatic rotator. It seems like a rather obvious product that's available from other manufacturers but missing from their lineup. It's possible they have one in the works which will complete the dream of a fully autonomous imaging system. ZWO, if you secretly have one of these in the wings, send me one for testing, pretty please!


The Wrap-Up

If you are just starting the hobby or building a new rig and are willing to commit to the ZWO ecosystem, the ASIAir Plus is a perfect addition to your setup that will make your entire process easier. I know that they will continue to add features and updates to the ASIAir app, which they have done since the release of the original ASIAir, bringing it closer to being toe-to-toe with any of the PC-based software in an easy-to-use, portable system.

Lastly, I'll leave you with the first light image acquired through the new ASIAir Plus.

📷 Camera: ZWO ASI1600mm-cool

🔭 Telescope: William Optics Gran Turismo 81 IV

📡 Mount: Skywatcher EQ6-R Pro

     ASIAir Plus
     Pegasus Power Box Advance

🌟 Exposures / Filters
      Astrodon Ha 1.25 5nm: 340x180" (gain: 139.00) -15C
      Astrodon OIII 1.25 3nm: 194x300" (gain: 139.00) -15C

⏳ Integration Time: 33h 10'

Crescent & Soap Bubble Nebulae


Sunday, December 5, 2021, 13:56
Known issues of the ASIAir, yet ZWO still sells them.<br /><br /><br />