I am the creator of Candid9 and I have taken about 290 photos of strangers and distributed them via candid9 QR codes. Happy to chat about it!

Thanks for replying and congrats on releasing your idea to the world. I just signed up to check it out and will use it in parallel with my project. I like your idea of session-based versus photo-based and also the approach of pre-printing QR codes. That is a simple workflow quite accessible to the less technical on both sides.

I don't think I have specific questions now, but I'm excited for the kinds of interactions it can spark. I mostly imagine getting lost in a sea of QR codes if it is not managed well. I was going to try to composite an extra copy for photographer reference.