QR codes are often misunderstood when they're on media other than paper or computer/phone displays. In particular, with projection-style displays like one migh

QR codes are often misunderstood when they're on media other than paper or computer/phone displays. In particular, with projection-style displays like one might find at a conference, the reflective surface of the backdrop will actually confuse a lot of QR sensors. Any glare and what's supposed to be black will actually come through as black with some white in it. The QR won't validate. The naked eye can't always discern that this happens, or why this happens. If it's a presentation given in pitch blackness, I'd say go for it. If there are other sources of light in the room, I'd at the bare minimum do some testing and be prepared to not put it up there. One other consideration. If someone walked up to you on the street and said they would offer you $10,000 if you could scan a QR code they showed you in 20 seconds, could you whip your phone out and launch/use a QR-scanning app in that much time? I know I couldn't, and I suspect most conference attendees couldn't either. If all you're shooting for is a youtube video where the people at home can scan the code, then ok, but I think QR is a solution looking for a problem here.