Creator of Lunar here. Thank you all for the kind comments and generous donations and many thanks to the OP for posting this!
Let me know if you have any questions or quick feedback about Lunar.
Thanks for writing this! When I got an iMac Pro in 2017 with an accompanying LG UltraFine 5K display I was shocked to learn three things: 1) adjusting the brightness on the internal display is easy but on the LG it's a pain in the ass, 2) despite having ambient light sensor hardware the LG does not automatically adjust its brightness like the internal display, and 3) macOS offers no built-in mechanism to sync the brightnesses of these two displays.
Before learning these things I was feeling excited about Apple's re-committing to the Mac around that time, but man these things made it feel like such "commitment" was just surface level - such low-hanging fruit not being handled is a shame. But, this is a rant for another day.
Anyway, I built my own very simple utility to poll the internal display for its brightness and write that same brightness to the LG via DDC, but never had the time/energy to make it more robust for publishing to the web. I have yet to try Lunar but I definitely will; much appreciated.
Quick feedback: I tried it for the first time, thinking to myself 'wow I really want to turn down the brightness on this darn monitor...its been bothering me for too long' and I didn't find the UX very easy to perform that immediate task. In fact, I have to say, just from quickly downloading this and trying to use it, I don't totally understand what it does...but I did figure out how to manually drop the settings to a more comfortable level, and I don't expect I'll be opening the software again except to manually turn it up and down (and each time I'll probably have to figure out how to go to that side page that is hard to get to)
Hope that made sense! Thanks for the software!!! :)
Hey thanks for the feedback! I know the UI is a bit too complex at the moment. It's hard to strike a balance between simplicity and configurability. It's still a work in progress.
So what does this do:
Lunar allows you to change the hardware brightness and contrast of the monitor (the one that can be controlled with the hardware buttons on the monitor)
If you simply want to turn down the brightness from time to time, you can set Lunar in Manual mode and use the brightness keys on your keyboard to adjust the monitor brightness.
Where Lunar shines is with a MacBook or iMac where there is an ambient light sensor integrated in the device that adapts the builtin display brightness. In Sync mode Lunar can sync that already adapted brightness to your external monitor so you don't have to worry about the brightness throughout the day.
There's also a Location mode if you want the brightness to adjust automatically based on the sun position in your location.
All this can be controlled through hotkeys which are visible in both the menu bar icon menu and the Hotkeys configuration page reachable by pressing the left arrow key 2 times in the Lunar UI.
Yes, there are no brightness change events, but reading the brightness is very fast so polling adds very little overhead.
For analytics I've just been using a plain nginx route that logs the request body to a static file, and I parse that using loki for further visualization in Grafana. I haven't found much value in that info though so I've decommissioned it after I migrated from nginx to Caddy. I'll remove the analytics request in the next update.
Your app has been a godsend for my multimonitor setup, Macbook in clamshell mode. I tried a bunch of tools, but eventually gave up frustrated after crashes.
Love Lunar since I discovered it, it’s been working smooth from day one.
Hi there, I couldn't find a way to disable built-in logging & analytics to log.lunar.fyi. Is there a setting to disable any network requests other than for software updates? Thanks!
Hi! The route for log.lunar.fyi just returns 200 now and doesn't do anything. I was just logging the request before but I disabled that in the meantime since I didn't find it useful.
I will disable the request completely in the next update, but if you want to know what's sent or even disable it completely you can take a look at the source code of the sendAnalytics function in AppDelegate.swift: https://github.com/alin23/Lunar
Absolutely amazing application - I found it on HN sometime at the beginning of COVID lockdowns, and it has radically changed my WFH life. Thank you so much :D
I use it with 2 disparate non-thunderbolt monitors, one connected into its built-in dock, and the other to a dock dongle. Works perfectly fine!
There is a problem with "cheap" monitors and DDC/CI: some of them use EEPROMs to store brightness settings, and this limits you to about 100,000 writes.
Worrying about this is the main reason we don't ship DDC/CI with f.lux. (I know that some more modern monitors use NAND and don't have limitations like this.) Anyone know if these fears are overblown?
This program should make sure to change brightness enough to reduce the lifespan to less than 2 years. Then the user will have free lifetime updates of monitors! (I reckon this would fall perfectly within normal use of a monitor. Hence, an RMA case will kick in)
I tried to achieve basically what this app does on manual mode some years ago. “How hard could it be?” are the famous last words etched in the three ATI video cards I bricked before giving up.
For things like setting brightness or toggling devices that ought to be dead simple, stuff like DDC/CI and HDMI-CEC being broken on so many levels never fails to make me spectacularly sad.
Not related to monitors, but this is how I bricked my old Lenovo Thinkpad W520 4 times. I switched between the Intel and Nvidia GPUs via the BIOS setting enough times to wear out the BIOS chip. I didn't figure out what was going on until my 3rd replacement.
I suppose it's a type of problem that solves itself: If companies are dumb enough to store brightness settings in EEPROM, they're only doing it because no one uses DDC/CI.
Use DDC/CI, and they'll stop. Even NAND is wrong if brightness is actually dynamically controlled, it should just be RAM.
Ahh, but this information needs to make it to consumers so they don't get stuck with dud monitors that have internal storage that rapidly wears. How, as a consumer, do I know which monitors store settings in such a manner and therefore avoid them when making purchasing decisions? Perhaps Lunar and Flux could make monitor recommendations with affiliate links, Wirecutter style. I don't want to have to research, just tell me what works best so I can pull my credit card out.
Such monitor recommendations could only be based on people tearing down things, which is outside the scope of Lunar and f.lux.
There is never a guarantee that you don't get stuck with a dud monitor, in any aspect. However, companies making products with bad reliability is going to face high support/warranty fulfillment costs and get a bad reputation. And if it fails within warranty/consumer protection periods, you lose nothing.
So, write away, and flood bad manufacturers in complaints. It's all you can do as a consumer - the alternative boing to get AMD, nVidia or Intel (or Displayport/HDMI interest forums) to be interested in making requirements against display manufacturers on the matter.
Wait...so after the 100.000th write, your monitor will be forever stuck on the brightness it was set to that time?
BTW, assuming I change brightness 20 times per day, that would still give me 5000 days ≈ 13,5 years of service. By that time I definitely hope to use a different monitor than today
No, after 100.000th write your monitor is toast because the EEPROM died. Also note that most people change brightness in increments, with each step causing a write.
You could pay to buy monitors for people and ask them to toggle the brightness until it dies, then record it down on a wiki and opensource this information.
I've been reading that NAND flash doesn't support erasing individual bytes, while EEPROM does. If there's some way to attempt this and know the outcome, maybe that's a way to figure it out.
Early EEPROM could only be wiped entirely (but as this was done electrically, it was still an improvement over UV-erased EPROM), while EEPROM at the time of Flash's creation could often be byte-erased (as is the case now).
Nowadays "EEPROM" mostly refers to small, slow, rarely written config storage for microcontrollers. As thus, they are also usually accompanied by low write/erase endurance despite their byte-erase granularity.
Flash was meant as a higher capacity/performance version indeed sporting full block erasure as a downside, but nowadays it has supplanted EEPROM in all categories but small micro-controller usages. Plus, as capacity is now cheap, high write loads can easily be supported with write levelling (that is, writing to new locations instead of erasing/writing the same block over an over.)
The problem is that eeproms don't do wear leveling. Not internally and they're usually controlled by a simpler microcontroller that doesn't have enough resources to do it in software.
So every time you write to three same byte you're writing the same cell. 100.000 cycles is actually much more than current flash generations.
These days basically every kind of mass storage device you will use has its own dedicated controller chip which is pretty much a cpu with its own RTOS now. Those 2 cent 8kb eeprom ICs don't but its crazy how complex something like an sd card is.
Hmmm. I hope the firmware authors weren't that dense. I would imagine they do a write when you exit the brightness change menu.
100,000 is a typical eeprom guaranteed write count. It will likely last much longer. The eeprom is probably much bigger than they need for such an application so they could actually handle the wear case by moving to alternate locations when write failures occur.
> Hmmm. I hope the firmware authors weren't that dense. I would imagine they do a write when you exit the brightness change menu.
This is not an option when using DDC/CI, where each brightness change is an isolated command. Plus, the OS is likely to emulate a smooth transition by sending even more commands than the end-user dictated.
Sure, the firmware could defer storing to EEPROM until a timeout from last command, but I would not credit the average display firmware as being that thoughtful.
> 100,000 is a typical eeprom guaranteed write count.
No, it's usually an estimated write endurance at a certain voltage and at 25°C, with the number based on calculated risk of failure being lower than a non-zero threshold. Higher temperature and voltage leads to higher failure rates.
I have dealt with several EEPROMs dying after just thousands of writes, including ones in products manufactured at a previous employer (where the EEPROMs were replaced with modern flash). Reserve EEPROMs for when writes are the exception.
I tried to find a source for these concerns. Although I can find documentation on DDC (until 1998) and EDDC (since 1999), and indeed read that these often use EEPROM, I cannot find any reference of someone who broke his monitor by changing the brightness too often.
This utility is very useful combined with the adaptive brightness of my iMac so I am tempted to use it. But I would appreciate any supporting evidence of this concern.
You never know if a wear leveling algorithm has been implemented so flash type isn't going to make lifetime determinable. Even without, 100 erases a day will last for 3 years or longer.
My monitors rarely last that long (at least, before I find it's worth it to upgrade), but like a lot of folks, I put most of my money into good monitors, keyboards, and color laser printers rather than the computers themselves, because I can generally get at least 5-10 years out of the peripherals. Computers themselves rarely last me more than 3-4 years, although my wife still uses one of my old Surface Pro 3s as her main computer - it's held up better than the SP4s.
If I could get a pair of Surface Studio touch monitors to dock with a Surface Pro/Book, I'd buy them, but yeah, I'd be real careful with them, too...
Also note that MonitorControl [1] might be a good complement to this program - it allows manual setting of brightness and contrast, but also adds volume control.
Lunar also has volume control, could not fit that into the title.
It's absolutely great, totally what I needed for years. Other tools I tried crashed my Macbook. Lunar has been absolutely smooth, and great design to boot. I immediately bought the author a coffee.
The volume keys on my Apple Magic keyboard just started working with my LG. It seems the monitor needs to have a speaker and be the audio-out device for this to be active.
Oh man I’ve been looking for something to control volume like this forever. Doing audio over DisplayPort/HDMI locks me out of controlling volume (since it’s handled by the monitor) so I’m really hoping this helps with that.
My experience has been that my monitor has limited volume control capability (compared to the knob on my external speakers, which are plugged into the monitor).
I combine this with https://github.com/nriley/brightness to retrieve the brightness of the main screen, then I use ddcctl to apply it to the external screen.
I set it up in a cron job and that has been running for years now. (the external monitor brightness is not very linear though, so you need to fiddle a big to find the proper/acceptable matching)
Got a MacBook Pro (16-inch, 2019) weeks ago and bought a LG monitor (https://www.amazon.com/gp/product/B07YGZ7C1K). The brightness setting bothered me for 2 weeks as neither the Mac OSX nor LG's onscreen control software can set the brightness for the external monitor. The external monitor brightness changes every time I open/close the macbook lid. Thanks to both ddcctl and MonitorControl, I can finally set a fixed brightness. Wondering why big corps fail to provide the basic features while some open source software can do?
How have you found MacOS' font rendering on the 1440p display? I've been having all sorts of trouble in some applications having terrible font rendering while others are perfectly fine running at the monitor's native resolution.
The LG UltraFine displays do support this (in fact there's no OSD/controls on the physical things at all) so it definitely is possible and something LG can do
Automatic dimming only works in the recently refreshed (mid 2019) UltraFines. It doesn't work in the original models sold from 2016-2019, despite advertising and product documentation claims that it does.
This is a great example of why I like the Touch Bar on my Macbook Pro. When it is connected to an external monitor, I tap the brightness icon in the Touch Bar and get two sliders: one to control brightness on my laptop, and one to control brightness on my external monitor. This seems to be a native feature; I did not install anything to do it.
But why can't they expose these controls independent of the Touch Bar? I actually find it ridiculous as a 2015 MBP owner that there is no easy native way to do this basic thing unless, apparently, you have a Macbook with a Touch Bar
F1-F2 to change MBP brightness, CTRL+F1-F2 to change external monitor brightness. Works with my thunderbolt LG 5K. (I dislike the Touch Bar so I always use an external keyboard when at my desk)
They are independent of the touch bar. It simply presents a UI for any external monitors for which macOS already knows to control the brightness. You can change the brightness of supported monitors from System Preferences or using the keys on compatible keyboards.
I agree. There are brightness sliders for each screen in System Preferences, but doing it that way is a pain in the butt for something that I do frequently.
My previous laptop was a 2012 Macbook Air, and I used an Apple Bluetooth keyboard at my desk in part for this reason. The laptop keyboard adjusted the laptop screen brightness, and the BT keyboard adjusted the external screen brightness.
Mine is an old Apple Thunderbolt 27" external display.
It didn't occur to me that the Touch Bar control might be specific to this display, since the display predates the TouchBar by many years. But maybe it is, since you and other commenters don't seem to see it.
See, my granny would have a hard time with this because while us young folk can control two sliders at once with ease, she would go as crosseyed as dead ol' Bessie was when we found her out back last year. Apple seems to expect more and more of us - soon we'll all be forced to be DJ's just to use our cell phones (har har!)
I have been using this command line tool to control my external monitor from my Mac. I created few Automator scripts calling it to make the monitor either dimmed or bright.
With my LG 32UL950-W, I've found that whether it responds depends on the cable choice. I had to give up on Thunderbolt because the monitor itself kept resetting; HDMI delivers a picture but doesn't look as good, and doesn't respond to ExternalDisplayBrightness. I'm now using a 10' USB-C to DisplayPort cable (too long for Thunderbolt) and everything works, including ExternalDisplayBrightness.
I'm curious to see if switching to Lunar would gain me anything.
The Windows equivalent would be Monitorian (https://github.com/emoacht/Monitorian). It doesn't have the adaptive curve algorithm, but I've been using it for over a year and it's indispensable.
Cool idea, but I'm a software developer and I cannot figure out how to use this app. Something as simple as monitor brightness doesn't need so many controls, toggles, and things popping up and telling me things. It doesn't follow a single MacOS design convention.
I'm not sure why you're being downvoted but I really struggled with this application as well. Sync mode? location mode? There's help text, which I read it several times and I still have no idea what's going on.
The preferences screen is very difficult to use - it's a mix of labels and buttons with no indication that things are adjustable. You can adjust the brightness by hovering over the brightness amount and scrolling vertically. There are multiple preference panes, but they're only findable with horizontal scrolling. None of this is easily discoverable.
I use the software... but pretty much only the shortcut keys (^F2, ^F1). The other features which seem like they could be useful, would probably see a lot higher adoption if the application followed some UX best practices.
Different users have different needs. The app was extremely simple when I first launched it because I only needed an UI for ddcctl.
But as I was gathering feedback from users, I wanted to make Lunar usable in as many monitor setups as possible. And very good ideas came out of that (Sync mode being one of them) but it also cluttered the UI with a bit too many configurable values. Those are still needed by some users even though they might not seem useful for you, so I don't want to remove configurability.
I think by adding all these knobs, Lunar achieved the goal of being flexible enough to conform to most types of monitor usage. Now I just have to figure out how to simplify all this without losing flexibility.
Off topic but tangentially related: Is there a brightness tool for the iPhone that has a better colour profile that harmonizes "dark mode" and "light mode"?
On my iPhone 11 late at night, turning the brightness down to 20% makes black text on white readable, but if I switch to a dark mode app, it's not comfortable, so I have to turn the brightness up again. To me, that implies the brightness just linearly applies to the whole colour spectrum, when it'd be better to weight the brightness logarithmically: Colours close to the dark should stay the same at both 20% and 100% brightness.
I'm not sure if this is even possible on an iPhone. I don't have the same problem on my external Dell screen with my Mac, not sure why.
I'd settle for the Mac being smart enough to let me resize each external display to its actual physical size, so dragging between them works. Apparently, Apple thinks it's perfectly OK to assume that all your displays have the same pixel density as your laptop screen - FAIL!
I seem to be able to set scaling on both of my monitors separately... so not sure what you mean. Actually I think on the external display there might be a keyboard shortcut to set common resolution equivalents for the scaling even on lower dpi screens.
Lunar should work just fine with f.lux as it only changes the monitor hardware brightness. Color processing from f.lux can still be applied on top of that without any issues.
I've been using Lunar with Night Shift ever since it was released in macOS and they complement each other very well at night.
Thanks for making this. Light years better than the original app I was using as it lets me change the volume stepper control, though the scroll/swipe motions in settings are bit jarring to use.
Up/down arrow keys can also be used to adjust values in the UI while the cursor is on a value.
I mostly use scrolling for rough adjustments and arrow keys for fine tuning. It feels faster than simply editing a text field. Although I'm planning to make the fields editable in the future as a lot of users have requested that.
Thank you for making this! I used to have to unplug my external monitors and use only my laptop screen at night because they used to be so bright. Always wanted something like this.
I should add that both monitors are connected via DisplayPort. Also, I found that cheap DP cables can really mess things up. Eventually I found via the VESA website which manufacturers have their cables certified. My go to is called Accell, very solid ever since using their cables.
Hey, glad it took off and got you and Lunar some exposure. I’m grateful for it being available free and solving a rather large annoyance. You are obviously very talented, keep up the good work!
Been using MonitorControl for a while now, and it was great but this is far nicer in my opinion. Great work. The only downside is before I saw this discussion I was happily using MonitorControl and now I'm using Lunar scared to death that one day both of my expensive 4k monitors will just be bricked due to the whole DDC/CI/EEPROM 100,000 writes deal discussed by @herf
I have an LG Ultra HD monitor and I have been using Lunar with smooth transition for 2 years now. I have far exceeded the 100k writes mark, probably even more than 500k and I see no problem with my monitor. I think new monitors should be immune to this since RAM and flash storage is so much cheaper nowadays.
Neat! I just got a new screen with DDC/CI and was excited to get that control with Dell Display Manager on my desktop rather than digging through OSD menus. I wish it would just go in the action center like a laptop's built-in screen, but it's still more convenient than using the buttons.
Will have to try this out when I get it hooked up to my Macbook!
What a nice little tool! I have two random no-name adapters at work for my two monitors. One is DisplayPort, and the other HDMI. I wasn't expecting this to work, but sure enough, it does! Both monitors show up and promptly respond to my brightness settings.
Love the utility! Been using it for a few months now. I’m curious, but is it possible to have the tool change inputs as well? For example, to change from DisplayPort to hdmi, and back from a keystroke.
Only part of that is possible, changing from the current input to another. But as soon as the monitor is on another input it doesn't accept DDC messages on the first input anymore so Lunar wouldn't also be able to change back.
I plan to implement just the first switch along with a brightness/contrast reset to some default values so you can easily switch the monitor to another input.
This is usually a hardware problem. I haven't found an easy way to detect if a GPU+monitor combination will have a very slow response time for DDC messages so all I can do in Lunar is send the messages to the monitor and if a number of messages fail then Lunar stops sending them to keep the system usable.
But there are cases like yours where the response time is so slow that the kernel panics in the first DDC message and freezes the whole system. There's no way to detect or recover from that in software.
I guess it makes sense to have that setting per monitor. I just have to rethink the monitor settings UI because it seems I can't fit anything else in there.
I already have a lot of users telling me that the UI is too complex.
