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For this week's giveaway, we've teamed up with Astropad to offer MacRumors readers a chance to win a Luna Display adapter that's able to transform an extra Mac or iPad into a secondary display for your primary Mac.

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Priced at $80, the Luna Display adapter is a small dongle that plugs into your Mac using a USB-C port (on newer Macs) or a Mini DisplayPort and when used in combination with the Luna Display software, your main Mac (or a PC) can be connected to an iPad or another Mac over WiFi, giving you a new way to take advantage of old hardware or add an extra display without having to invest in another device.

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When connected, the Luna Display extends the primary Mac's display to the secondary Mac or iPad to allow the extra device to be used as a second screen, which is useful as people continue working and learning from home with makeshift office setups in 2021.

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The Mac and iPad have built-in Sidecar functionality that can turn an iPad into a secondary display for a Mac without an accessory, but the Luna Display sets itself apart with the Mac-to-Mac support, which Sidecar can't do. Luna Display is also able to work with older iPads that don't support Sidecar.

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In Mac-to-Mac mode, the primary Mac needs to have OS X El Capitan or later installed, while the secondary Mac can be running OS X Mountain Lion or later, so Luna Display works with machines that are quite old. For best performance, the main Mac should be a 2012 MacBook Air, MacBook Pro, Mac mini, iMac, or later, or a 2013 Mac Pro or later. As of November 2020, the Luna Display adapter has native support for M1 Macs, too.

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Luna Display offers full keyboard, trackpad, and mouse support on both connected Macs in Mac-to-Mac mode, with more information on how it works available on the Luna Display website.

For iPads, the Luna Display is compatible with almost all modern iPads, including the iPad 2 or later, all iPad mini models, all iPad Pro models, and all iPad Air models, with iOS 9.1 or later as the only requirement. Performance is faster on newer iPads, but older models work well too.

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For those who have PCs, there is a Luna Display adapter for Windows. The PC version of Luna Display extends your desktop from PC to iPad, allowing your devices to work interchangeably.

We have five Luna Display adapters to give away to MacRumors readers. To enter to win, use the Gleam.io widget below and enter an email address. Email addresses will be used solely for contact purposes to reach the winners and send the prizes. You can earn additional entries by subscribing to our weekly newsletter, subscribing to our YouTube channel, following us on Twitter, following us on Instagram, or visiting the MacRumors Facebook page.

Due to the complexities of international laws regarding giveaways, only U.S. residents who are 18 years or older and Canadian residents (excluding Quebec) who have reached the age of majority in their province or territory are eligible to enter. To offer feedback or get more information on the giveaway restrictions, please refer to our Site Feedback section, as that is where discussion of the rules will be redirected.

The contest will run from today (April 2) at 11:00 a.m. Pacific Time through 11:00 a.m. Pacific Time on April 9. The winners will be chosen randomly on April 9 and will be contacted by email. The winners will have 48 hours to respond and provide a shipping address before new winners are chosen.

Article Link: MacRumors Giveaway: Win a Luna Display Adapter to Turn Your iPad or Mac Into an Extra Screen
 
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Yeah, this used to be a thing long time ago. But now that iOS comes with built-in screen sharing function, these dongles are quite useless for Mac users. Also, there are free screen extender app for Windows users as well.
 
What's the difference in latency between the two methods?
depends on the connection method for both. If wired (usb cable), there is no latency at all. For using WiFi, I haven't notice any delay as long as I have a good connection/router (i.e. poor wifi signal in cafe introduce 50-200ms delays).

EDIT:
To add comparison between built-in screenshare and Luna, it is no brainer. Luna relies on dongle which means you cannot do wired connection.
 
Yeah, this used to be a thing long time ago. But now that iOS comes with built-in screen sharing function, these dongles are quite useless for Mac users. Also, there are free screen extender app for Windows users as well.
Wrong on so many levels. As someone who uses both, the sidecar is terrible and crashes every time you change a setting. Luna performs better, has lower latency and can run headless. There are other features that I'm sure other people will use, but 1 to 1 luna crushes sidecar on every level except letting it function as a 3rd monitor on the M1 Macs (sidecar doesn't count as a monitor, where luna does)
 
Wrong on so many levels. As someone who uses both, the sidecar is terrible and crashes every time you change a setting. Luna performs better, has lower latency and can run headless. There are other features that I'm sure other people will use, but 1 to 1 luna crushes sidecar on every level except letting it function as a 3rd monitor on the M1 Macs (sidecar doesn't count as a monitor, where luna does)
This almost feels like a Luna advertisement lol.
 
Wrong on so many levels. As someone who uses both, the sidecar is terrible and crashes every time you change a setting. Luna performs better, has lower latency and can run headless. There are other features that I'm sure other people will use, but 1 to 1 luna crushes sidecar on every level except letting it function as a 3rd monitor on the M1 Macs (sidecar doesn't count as a monitor, where luna does)

And you forgot to mention that all the secondary monitor app like Duet and Luna has been suffering for many years due to the changes in macOS and 3rd party apps not being able to access graphic drivers (look at all those 1 star app reviews 2-3 years ago). IDK if they fixed it by now or have a work around but who knows if that happens again.

Also, can you provide the source for your claims? I highly doubt that bluetooth wireless dongle can out perform wired connectivity in any way.
 
For what it’s worth, I bought one of these and swiftly returned it. The lag is awful. I used it between an iMac and MacBook Pro, both of which are relatively new Macs. And I use Ubiquity wifi access points at home. I can’t imagine that my setup was the culprit in having a poor experience with Luna.
 
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And you forgot to mention that all the secondary monitor app like Duet and Luna has been suffering for many years due to the changes in macOS and 3rd party apps not being able to access graphic drivers (look at all those 1 star app reviews 2-3 years ago). IDK if they fixed it by now or have a work around but who knows if that happens again.

Also, can you provide the source for your claims? I highly doubt that bluetooth wireless dongle can out perform wired connectivity in any way.
I'm not sure what you are talking about? It connects via wifi not bluetooth, but to remove latency altogether, you can use a normal lightning or USB-C cable that your iPad uses to connect back. It'll take up another port but it works perfectly. There is also a latency monitor for the Luna Display, but I am not 100% sure if there is one that exists for sidecar, if there is I'd be more than glad to take screenshots. I have never had any issues with the graphics drivers and I've been using it since the 2017 iMac. No issues at all with the M1 mini.

If you want to test sidecars bugginess yourself, just open up the sidecar preferences while connected and start checking/unchecking some of the boxes RE: Touch Bar and sidebar, it will disconnect with timeouts, at least mine does, all the time, and it has plenty of issues with sleep. God forbid you try to change the resolution while using it.

Another bonus, Luna lets you use the apple pencil as well as your finger, where sidecar forces you to use Apple Pencil.
 
And you forgot to mention that all the secondary monitor app like Duet and Luna has been suffering for many years due to the changes in macOS and 3rd party apps not being able to access graphic drivers (look at all those 1 star app reviews 2-3 years ago). IDK if they fixed it by now or have a work around but who knows if that happens again.

Also, can you provide the source for your claims? I highly doubt that bluetooth wireless dongle can out perform wired connectivity in any way.

a.) It's not a bluetooth dongle. Video is transfered over IP via wifi or optionally over usb-c (mac > ipad) and ethernet/thunderbolt (mac > mac)
b.) It has no problem accessing the graphics drivers because it doesn't need to. The dongle is used to simulate an external DP connection. If macOS makes a change to screw this up, then it screws up external displays for everyone.

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I'm not sure what you are talking about? It connects via wifi not bluetooth, but to remove latency altogether, you can use a normal lightning or USB-C cable that your iPad uses to connect back. It'll take up another port but it works perfectly. There is also a latency monitor for the Luna Display, but I am not 100% sure if there is one that exists for sidecar, if there is I'd be more than glad to take screenshots. I have never had any issues with the graphics drivers and I've been using it since the 2017 iMac. No issues at all with the M1 mini.

If you want to test sidecars bugginess yourself, just open up the sidecar preferences while connected and start checking/unchecking some of the boxes RE: Touch Bar and sidebar, it will disconnect with timeouts, at least mine does, all the time, and it has plenty of issues with sleep. God forbid you try to change the resolution while using it.

Another bonus, Luna lets you use the apple pencil as well as your finger, where sidecar forces you to use Apple Pencil.
huh, now I am more confused on why we have the dongle in the first place. The only reason for having a dongle would be providing bluetooth so it can connect to nearby devices. But if it uses WiFi, then why can't we just use the wireless card that comes with the Mac itself?? Also, if that dongle really comes with WiFi chipset in that tiny enclosure, will it provide a stable connection at all?

For Apple's built-in Sidecar, the performance is great. I use it as secondary monitor while coding, as controller during presentation (using fingers), and as mirroring screen when tutoring someone. Although there were some minor glitches when it first launched a year ago, it has been very stable and bug free now. I haven't encounter the issues you mentioned so perhaps, it is a problem on your end.

Going back to the topic, you don't have any source nor metrics to prove the performance of Luna. And yet, you claim that it "crushes" sidecar for everything. However, my educational guess says otherwise. Luna adds extra layers to the operation of extending screen. It requires communication with the dongle, establish connections with iPad through the 3rd party app (lots of overhead), then finally output the screen. Sidecar, on the other hand, is integrated in OS-level. Meaning, it skips many layers that the 3rd party requires.

Anyway, I am not here to bash on Luna. As I mentioned earlier, this used to be a thing long time ago. But as many features that Apple stole or implemented in newest OS, secondary screen apps are depreciated. Plus, the costs. $70 just for the hardware, and if you want to use all of their features, you have to pay for their subscription (kidding?). All I need to do for Sidecar is to click on Airplay on my Mac, select iPad, and enjoy the free and better performing screen sharing/extending.
 
b.) It has no problem accessing the graphics drivers because it doesn't need to. The dongle is used to simulate an external DP connection. If macOS makes a change to screw this up, then it screws up external displays for everyone.
I have to be corrected, it was hardware acceleration that was causing problems not the graphic drivers (my memory isn't always clear :( )
 
huh, now I am more confused on why we have the dongle in the first place. The only reason for having a dongle would be providing bluetooth so it can connect to nearby devices. But if it uses WiFi, then why can't we just use the wireless card that comes with the Mac itself?? Also, if that dongle really comes with WiFi chipset in that tiny enclosure, will it provide a stable connection at all?

For Apple's built-in Sidecar, the performance is great. I use it as secondary monitor while coding, as controller during presentation (using fingers), and as mirroring screen when tutoring someone. Although there were some minor glitches when it first launched a year ago, it has been very stable and bug free now. I haven't encounter the issues you mentioned so perhaps, it is a problem on your end.

Going back to the topic, you don't have any source nor metrics to prove the performance of Luna. And yet, you claim that it "crushes" sidecar for everything. However, my educational guess says otherwise. Luna adds extra layers to the operation of extending screen. It requires communication with the dongle, establish connections with iPad through the 3rd party app (lots of overhead), then finally output the screen. Sidecar, on the other hand, is integrated in OS-level. Meaning, it skips many layers that the 3rd party requires.

Anyway, I am not here to bash on Luna. As I mentioned earlier, this used to be a thing long time ago. But as many features that Apple stole or implemented in newest OS, secondary screen apps are depreciated. Plus, the costs. $70 just for the hardware, and if you want to use all of their features, you have to pay for their subscription (kidding?). All I need to do for Sidecar is to click on Airplay on my Mac, select iPad, and enjoy the free and better performing screen sharing/extending.
Thats fine its just that you have a misunderstanding about the hardware.
The dongle isn't really a bluetooth/wifi adapter. Its a literal monitor and it taps straight into the GPU, where I believe sidecar is CPU rendering (don't 100% quote me on that)

Luna requires no subscription, though I use it in conjunction with Astropad standard. Astropad Studio requires the subscription.

Short of recording a demo I don't really know what I can do to show you the difference. I drew a few circles in Krita just now in both, wirelessly, and the results are subtle but clear, Luna keeps its arcs, where Sidecar has a few jagged edges and oddly reads the pressure sensitivity weirdly (thinner in certain points and larger jumps in pressure changes).

If I'm just using it at my desk, I use sidecar for the 3rd monitor (I also have a graphics display, so I don't really need to use the drawing features there), but Luna lets me turn my Mac mini into a laptop (assuming there is a plug nearby), and that your cannot beat. Though admittedly I don't know why sidecar doesn't have this feature, it seems simple enough to implement.

edit: I saw your other post, so, you know, ignore that part
 
I have to be corrected, it was hardware acceleration that was causing problems not the graphic drivers (my memory isn't always clear :( )
Fair enough. But I'm still not clear how this would be an issue. You can see in my screenshot, the dongle creates a DP connection and it's being driven by the Radeon chipset. It's hardware accelerated just like any other real external display would be. I cannot speak to Duet or other software based solutions. But I fail to see how Luna would have any issues here.

Regarding your other comments, I think you may be missing the fact that Luna does a bunch of things that Sidecar doesn't. Now are those things important to you and does it merit an extra $70? Maybe/maybe not. Will Apple eventually steal those features too and integrate them into Sidecar? Who knows. But until they do, there is a definitely a market for Luna. I'm a developer who runs mbp15" > imac5k as a primary display. The experience isn't perfect, but it's definitely usable. It is however not even possible with Sidecar.
 
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I have used Luna since Kickstarter. As someone who travels a lot it was great. I had a second monitor which made work a lot easier. Sidecar does a lot now so I use it less. I find it faster than sidecar but doubt I would buy one know, and guess a lot of people who would be a target market feel similarly. Great idea but Apple has severely limited its popularity, IMHO.
 
I use both Luna and Sidecar, and both have different strengths and weaknesses. On the whole, Luna tends to hold on to connections better than Sidecar for me, but Sidecar is my preferred on-the-road solution. Mostly though, Luna supports mac-to-mac which Sidecar does not, and thats useful often enough that I'd willingly pay to replace the dongle if I lost it.
 
I gave up on Sidecar because it keeps freezing Apple Pencil support after about five minutes, wired or wireless.

Hugely disappointing.
 
In this space, Sidecar probably meets most customers needs and the few who this is useful for is not enough to sustain a company with a hardware accessory.
 
I gave up on Sidecar because it keeps freezing Apple Pencil support after about five minutes, wired or wireless.

Hugely disappointing.
Did you report this bug to Apple. If not, why not. Apple will be able to investigate and resolve if done so.
 
I used Luna Display before Sidecar came out. Luna Display works better than Sidecar, as other comments have mentioned. I was a bit disappointed when Sidecar came out, I thought it would be a complete replacement for Luna Display, but Sidecar is laggy and crashy and depends on some kind of software based rendering, while Luna Display really is just seen by the computer as another monitor and is configured that way. In wired mode Luna Display is much more stable and has less latency than Sidecar; in wifi mode the latency is about the same in my experience.
 
I'm using the Yam Display (USB connection) and Yam Air (for Wifi) for extending my desktop to my 5 year old iPad, that does not support Sidecar. They're dead cheap in App Store and they do wonders, and the only lag I'm getting is because of the processing limitations of an iPad being that old.
 
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