It is pretty rare that someone sees the camera. A lot of times we are further away than you think with the camera and the Sony wireless mic system can reach further than you think. Like almost 100 yards but we aren't that far away. A lot of times for an outside prank like that the person filming is sitting on a bench and oftentimes I will sit sideways facing 90 degrees to where I'm filming so it looks like I'm looking at my phone or something in my lap. In places like Walmart we will have a shopping cart full but then do a similar thing where we are leaning over the cart but have the camera in our hands. That way is more likely to get seen but again you can be pretty far away to get the shot.
In the libraries we actually go in between the isles and put the camera and the wireless mic receiver on the book shelve and then walk away from it and leave it rolling.

My next video on the @pranks channel will be a behind the scenes look at how we film some of the stuff.

Filming can be pretty fun but hard to get the shots at the same time. I'm sure you know about a lot of the drama that happened over the last couple of years where a lot of the big pranksters were exposed for just doing staged pranks where they had actors in their videos.....etc. So clearly when you are trying to get real reactions you can blow an entire day of filming and not get good reactions....etc.