Screen ConfigureDisplay Brightness flakey

1
dear mario
the Psychtoolbox command to set display brightness is flakey on my MacBook Air. (That's the only computer I tested.)
Screen('ConfigureDisplay','Brightness',screen,[],brightnessSetting)
I've tried single stepping through my MATLAB code while watching the display and the System Preferences Displays panel. (Incidentally, the AutoBrightness command does reliably turn autobrightness on and off.)
The Brightness command with a value of 1 usually (but not always) increases the screen brightness. But, weirdly, the brightness slider never moves. So the screen brightness becomes 1, while the slider remains, e.g. at 0.5. Any operation that brings focus back to the Displays panel brings brightness back down to whatever the slider is at. This is not what I remember. My recollection is that setting the brightness also moved the slider. My guess is that the behavior changed in one of the macOS releases. I realize that this may be beyond our reach. I'm just mentioning it to alert others and in the hope that perhaps there is a way to fix it.

best
denis

AutoBrightness(screen,0);
brightnessSetting=1;
brightnessReading = Screen('ConfigureDisplay','Brightness',screen,[],brightnessSetting)
brightnessReading = Screen('ConfigureDisplay','Brightness',screen,[])



photo
Denis Pelli
Professor of Psychology & Neural Science, New York University
+1-646-258-7524 | denis.pelli@... | http://psych.nyu.edu/pelli/ | Skype: denispelli | http://denispelli.com
2
As with other bugs and issues, please post as an issue on github

On Jun 18, 2017 08:24, "Denis Pelli denis.pelli@... [PSYCHTOOLBOX]" <PSYCHTOOLBOX@yahoogroups.com> wrote:


dear mario
the Psychtoolbox command to set display brightness is flakey on my MacBook Air. (That's the only computer I tested.)
Screen('ConfigureDisplay',' Brightness',screen,[], brightnessSetting)
I've tried single stepping through my MATLAB code while watching the display and the System Preferences Displays panel. (Incidentally, the AutoBrightness command does reliably turn autobrightness on and off.)
The Brightness command with a value of 1 usually (but not always) increases the screen brightness. But, weirdly, the brightness slider never moves. So the screen brightness becomes 1, while the slider remains, e.g. at 0.5. Any operation that brings focus back to the Displays panel brings brightness back down to whatever the slider is at. This is not what I remember. My recollection is that setting the brightness also moved the slider. My guess is that the behavior changed in one of the macOS releases. I realize that this may be beyond our reach. I'm just mentioning it to alert others and in the hope that perhaps there is a way to fix it.

best
denis

AutoBrightness(screen,0);
brightnessSetting=1;
brightnessReading = Screen('ConfigureDisplay',' Brightness',screen,[], brightnessSetting)
brightnessReading = Screen('ConfigureDisplay',' Brightness',screen,[])



Denis Pelli
Professor of Psychology & Neural Science, New York University
+1-646-258-7524 | denis.pelli@... | http://psych.nyu.edu/pelli/ | Skype: denispelli | http://denispelli.com


3
done. thx.


Denis Pelli
Professor of Psychology & Neural Science, New York University
+1-646-258-7524 | denis.pelli@... | http://psych.nyu.edu/pelli/ | Skype: denispelli | http://denispelli.com

On Sun, Jun 18, 2017 at 2:42 AM, 'Diederick C. Niehorster' dcnieho@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:

As with other bugs and issues, please post as an issue on github

On Jun 18, 2017 08:24, "Denis Pelli denis.pelli@... [PSYCHTOOLBOX]" <PSYCHTOOLBOX@yahoogroups.com> wrote:


dear mario
the Psychtoolbox command to set display brightness is flakey on my MacBook Air. (That's the only computer I tested.)
Screen('ConfigureDisplay','Bri ghtness',screen,[],brightnessS etting)
I've tried single stepping through my MATLAB code while watching the display and the System Preferences Displays panel. (Incidentally, the AutoBrightness command does reliably turn autobrightness on and off.)
The Brightness command with a value of 1 usually (but not always) increases the screen brightness. But, weirdly, the brightness slider never moves. So the screen brightness becomes 1, while the slider remains, e.g. at 0.5. Any operation that brings focus back to the Displays panel brings brightness back down to whatever the slider is at. This is not what I remember. My recollection is that setting the brightness also moved the slider. My guess is that the behavior changed in one of the macOS releases. I realize that this may be beyond our reach. I'm just mentioning it to alert others and in the hope that perhaps there is a way to fix it.

best
denis

AutoBrightness(screen,0);
brightnessSetting=1;
brightnessReading = Screen('ConfigureDisplay','B rightness',screen,[],brightnes sSetting)
brightnessReading = Screen('ConfigureDisplay','Bri ghtness',screen,[])



Denis Pelli
Professor of Psychology & Neural Science, New York University
+1-646-258-7524 | denis.pelli@... | http://psych.nyu.edu/pelli/ | Skype: denispelli | http://denispelli.com



4

Actually that's not our fault. It was implemented and tested and it worked fine in the past on different MacBooks.


If it doesn't work properly now without me changing any related code then that's a macOS bug and should be filed to Apple:


https://developer.apple.com/bug-reporting/


Ideally with a copy to OpenRadar, so people can keep track if or how (or how poorly) Apple handles issues:


http://www.openradar.me/


Have closed the issue on GitHub as invalid.

-mario