Today I helped run some iMovie training for teachers at school, which was fun. Part of that involved rigging up a MacBook Pro to a projector in our training room, which also has an AppleTV connected to it. I was presenting Keynote slides, but also wanted to occasionally mirror an iPad to demo how to use apps like Educreations to do basic storyboarding. I was using Reflector to set up an AirPlay receiver, but it struck me that I should just use the AppleTV instead. After all, Mountain Lion lets you mirror your Mac’s screen to an AppleTV.
My problem with AppleTV from before was that the aspect ratios seemed to go a bit wrong when mirroring 4:3 content vs 16:9. I tried fiddling with the projector’s aspect ratio and putting it on some sort of widescreen zoom mode made a difference. However, I then installed an update on the AppleTV and set the projector to good old 4:3 (rather than ‘auto’) and it all seemed to work! Mirrored 4:3 iPads filled the screen, but also Keynote slides too!
So maybe AppleTV works better than I originally thought!