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Ask HN: Would QR codes be readable by a conference audience on the big screen?
I'm trying to work out if it makes sense to display QR codes on the big screen at a conference or event, if the people in their audience could read it.
I suppose the answer is "it depends", and in particular I'd want a very short URL.
Interestingly, I can easily read QR codes from 15 feet away on my PC screen by pointing my iPhone camera and zooming in.
But I'm interested to know if anyone has heard of this working?
- gus_massa 8y agoSorry, not idea about this, but if it works it looks like a very nice subject for a blog post in the future. (And if it doesn't work, a blog post may be interesting too.)
- barry-cotter 8y agoYes. I used my phone to log on to a wechat group chat Wednesday night from at least 10m away, probably 15m. Said QR code was on a big screen.
- LarryMade2 8y agoHmm haven't tried it but I would think it would work, it's all about focus and resolution, if you can take a clear shot of a PPT slide from the back row then QR should work too... How about this for a test - display a QR from a TV hooked to your laptop and try to scan it from the back of your room, with the lights dimmed and at various sizes... I think it ultimately depends on the focusing ability of whatever QR reader app you have.
- mchannon 8y agoQR 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.
- borplk 8y agoIf possible I suggest trying a few test runs before the real session.