I gave a presentation today using my MBA connected to an Epson projector. Prior to today I had plugged my Air into my TV via HDMI to practice the presentation. At home it worked fine with my Air displaying my presentation notes and current & upcoming slides and the TV showing the slides in full screen.
Get to the event and connect to the Epson projector via same MDP to HDMI connector. Bring up my presentation and the displays are in mirror mode. Fix was to go into Settings and turn off mirror mode. Smooth sailing from there.
Thing I can’t figure out is why the projector came up in mirror mode and my TV wasn’t. This was the first time I had used either device with my Air. Does the projector appear different to the OS than the TV does?
In short, yes. Projectors, monitors, and TVs all send information about themselves to your computer when you connect them. This article has lots of details if you are curious. Displays and EDID
Interesting information but it doesn’t really explain why the Air decided to make one connection a separate monitor and the other mirrored. I’m really trying to figure it out as a rebuttal to someone else there, a anti-Apple Google fanboy, that said it was Apple doing things in a non-standard method.
I connect to lots of different external displays. By default, when I connect to a new display for the first time, it is mirrored. After I changed it to extended, it remembers the setting for that display.
Apple treats some specific classes of displays differently. Projectors and AirPlay screens start in mirror mode by default, while the rest start in extended mode.
You can tell that someone else that there is no standard way to treat this, it’s just what every OS decides. And it makes sense for the projector to mirror, after all it is a device that “projects” your screen to a larger audience.
I guess in this case, using it in extended mode would be non-standard kidding, there’s no such thing
AirPlay has a similar use case, the most needed one being to “stream” your smaller screen to a larger TV.
Your OS also remembers different projectors and monitors and what your settings for them were. I regularly move between 3 different setups and it always remembers correctly.
This make really good sense. I guess the Samsung 4k TV looked like a monitor and the projector didn’t. Wasn’t a big deal but I just wondered why it happened. Thanks for the explanation.
Lunar
kidding, there’s no such thing