AMITIAE - Friday 24 October 2014
System Preferences in OS X 10.10, Yosemite: Displays
By Graham K. Rogers
DisplayThe Display pane appears similar to that in previous versions of OS X. As before, icons for the specific displays being controlled (internal or external) are used. On my computer, for example, the icon for the Retina display panel clearly shows a MacBook Pro, right down to the "MacBook Pro" characters, the black screen surround, the infrared detector and the iSight camera (you have to look hard).
The Mac's current desktop picture is displayed. If the desktop is changed (see, Mission Control) and the Displays preferences panel re-opened, the picture will change to the current desktop picture (See Desktop & Screensaver.
With the Retina display MacBook Pro the numbers are replaced with small icons, some of which have text descriptions below. When the cursor is placed over an icon, the Mac image on the panel changes to indicate how the display would look. A text describing the approximate resolution appears beneath the image. Selecting a new setting changes the Mac icon.
"Best for display" is for users who will want to leave well alone and will be content with the setup as provided. When this is selected, there is only a slider for Brightness and a checkbox below this, marked "Automatically adjust brightness." It is still possible to use the slider when the box is checked. When the Function keys (F1 and F2) are used, the slider moves as well.
On some Macs, such as the iMac I use at work, selecting "Scaled" reveals a box now with 4 options, from 1024 x 640 up to the optimal 1440 x 900. These resolutions cannot be edited, nor can we add any others. Below is the Brightness slider and the "Automatic" checkbox.
ColorThe pane marked Color is to show and, if necessary, add or change any color profiles by way of calibration. Most home users will not need this, but for imaging professionals this ability to calibrate displays is critical. While professional photographers or print houses may need to check calibration regularly, they will have specialist knowledge and equipment to assist with this.
There is a warning here: if you are not sure, don't touch.
The default display for the Mac is shown. Below is a checkbox marked, ""Show profiles for this display only". When this is unchecked, any profiles previously created are shown in the main window. Highlighting a profile will change the display to the specific settings for that profile. To the right are three buttons: Open Profile, Delete Profile, and Calibrate.
ArrangementWith Macs it has always been possible to set up the way an external monitor displays information, either by mirroring the main display (a clone) or a side-by-side setup. I normally use this for presentation of information in a classroom, using an overhead projector.
When displays are mirrored, the information on the screen is identical (See also information, below, and Mission Control).
Mission Control has a new option for displays to have separate spaces. This requires the user to logout for this to become available. (see notes below). When this is used, the Finder menubar is shown on displays that are not mirrored: greyed out when the external display is not the main window, but solid white when user clicks on the desktop of that screen. When the external display is the main window, the menubar on the Mac is greyed out.
Depending on which of the displays is selected as the optimal choice when Mirroring was on (Mac or external) an "Arrangement" pane will be added. In my case, when the Acer monitor in my office was shown on the "Optimize for" button, that panel had the three panels, while the Mac had the original Display and Color panels.
When mirroring was off, the resolution adjusted itself to the best for the respective display, so while the MacBook Pro was running in its optimum 1440 x 900, the Acer display was at a 1600 x 900 resolution.
By clicking on the white Finder bar at the top of the blue Window shown in the preferences display (image above) it can be dragged to another of the windows shown. With this, the window on the external display may become the main (Finder) window (see above).
On the external display panel on my computer, when mirroring is OFF, I also have a Rotation button. I added this some time back using a Terminal command in the main panel (see below), but it is now only shown when a suitable external monitor is attached.
With this, I am able to turn the display through 90, 180 and 270 degree options which may be useful when certain displays are used or some images need to be shown at different angles.
Comments on Displays in YosemiteThose having problems making presentations display correctly using the Mac and external monitors may also want to look at Mission Control where a checkbox, marked "Displays have separate Spaces" will affect the way presentations and (particularly) presenter displays are shown. When the box is unchecked, using displays that were not mirrored, the presenter display was on the MacBook Pro with the slides displayed on the external display (as in previous versions of OS X).
Graham K. Rogers teaches at the Faculty of Engineering, Mahidol University in Thailand where he is also Assistant Dean. He wrote in the Bangkok Post, Database supplement on IT subjects. For the last seven years of Database he wrote a column on Apple and Macs.
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