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Gamma Control 6 + Gamma Board

There isn’t a lot to change about a small app that has been working well for more than 15 years. Common wisdom would say that you shouldn’t change what works.

This new version comes with a couple of small improvements. For instance, you can click the calibration pattern to make it appear bigger in a separate window. Touch Bar support has been added for the proud owners of the newest MacBook Pros. Up and Down arrow keys will now increase and decrease the value in the selected field.

And you could call it a visual overhaul the fact that there is now a dark mode and it is enabled by default.

But for some of you, the most important feature of Gamma Control 6 will not be one of these small incremental improvements. If Gamma Control remains the reliable Mac app that changes little over the years, its new companion iOS app Gamma Board could change deeply how you interact with it.

Bluetooth keyboards are sometimes a convenient way to configure Gamma Control. It’s convenient that you can take a few steps back and hit tab and the arrow keys to adjust the colors while looking from afar. And calibrating from a distance is quite handy if you are about to include the screen in a shot and wants to look at the resulting colors through your camera.

But a Bluetooth keyboard isn’t that great of a remote either. It only operates when Gamma Control is the frontmost app. If you have multiple monitors it’ll only work for the current one. And most of its keys serve no purpose other than take space making the device less portable when operating Gamma Control. To improve all this, Gamma Board was created.

Gamma Board is the equivalent of a lighting board for an array of screens. It communicates with Gamma Control via Wi-Fi and lets you adjust all your screens from your iOS device. You can see and edit the settings of each screen, move the sliders, and save and restore settings for a set of screens belonging to multiple Macs all at once. All from one device you can put in your pocket. It’s easy to setup over the local network. And it’s super convenient for making screen adjustments from a distance.

If any of this seems appealing to you, take a look at the product pages for Gamma Board and Gamma Control 6.


Another Black Light Post

In my last post I said Black Light is working well with Night Shift. It appears that I overlooked something however. With some hardware configurations, the Invert Screen filter of Black Light no longer works except when Night Shift is active. This bug appeared in macOS 10.12.4 so it’s probably linked to some changes that were made in macOS in order to make Night Shift possible. That said, it also affects some models that do not support Night Shift.

If your computer is affected by this and it supports Night Shift, there is a workaround: manually activate Night Shift while Black Light inverts your screen. To minimize the color changes of Night Shift, set it to its lowest color temperature setting in System Preferences. If your Mac does not support Night Shift and you already upgraded to 10.12.4, you are out of luck. Sorry.

I filled a bug report with Apple (31521584) about how some gamma curves are ignored by the system and I’m now waiting a reply. Hopefully this will get fixed in the 10.12.5 update, but this remains uncertain at this time.


Black Light, Night Shift & Flux

Black Light and Night Shift are good friends.

Many users of Black Light also want to use Flux (or f.lux) to tint their screen in warmer colors at night. The problem is that you can’t use both apps at the same time: they each compete to take control of the screen’s gamma curve and the result is a unusable flashing screen alternating between the gamma settings of the two apps.

In yesterday’s 10.12.4 update, macOS Sierra added a Flux-like feature called Night Shift. The good new is that, unlike Flux, Night Shift works well with Black Light.

The mechanism used by Night Shift is different. It does not rely on the gamma curve, which is good as it’s not fighting with Black Light. This also makes it limited in the hardware it supports1. After applying the update, you can check if your computer has the Night Shift tab in Apple Menu > System Preferences > Displays.

There remains only one small caveat: Night Shift combined with the “Invert Screen” filter will tint the screen light blue instead of the expected yellow-orange. Other filters will combine well with Night Shift.

Also of note: Gamma Control works with Night Shift too.


  1. Night Shift is supported by all Macs introduced since 2012, excluding the tower-format Mac Pros. ↩︎


Using Black Light to Avoid Image Retention

My iMac slowly started showing signs of image retention (or image persistence) a few months ago. After leaving the screen on for a few hours, I’ll see the imprint of what was left unmoved for too long. It only happens near the edges, and it will fade after some time, but it can be a bit annoying.

My Black Light Preferences

This week I made a little discovery: if I use Black Light to dim the screen by the smallest amount it’ll let me, I get no image retention. Black Light dims the screen by making each pixel color a bit darker, not by dimming the backlight. I suspect changing all the white pixels to a very light gray prevents the liquid crystals from getting stuck.

This is anecdotal: I tested it on my own computer and only for a few days. I can’t be sure it’ll work with other screens that are experiencing image retention. But if your screen has that problem, I think you should give Black Light a try and see for yourself.



  • © 2003–2018 Michel Fortin.