Over the years I have developed my technique for photographing people without looking through the viewfinder. In the 1970’s I first became aware of The Heisenberg uncertainty principle. Although it really has nothing to do with the observer effect it does help to mathematically corroborate that principle. Simply stated the act of observing something changes that thing. I knew when I pointed my camera at people their behavior would change.
I thought to not have people react to me I had to photograph them in a stealth mode. First I employed telephoto lenses but since going digital I have began shooing without looking through the viewfinder. Wasting bits and pixels is a lot different than wasting film. I set the camera to a wide angle and select automatic focus and exposure. I get a lot of crap but then I also get shots like this one which make it all worthwhile. Next a mirror-less camera because people do react to the shutter noise if they are close enough.