One of the question I always had, how to do random street photography without making people mad when you're not in a big city? Here's my experience personally. When i am in a bigger city such as visiting Chicago, anything works, 35mm or medium format, people seems too busy to worry about you 3/4 of the time, or they will give you a stare and move on at the most. But when I am in a rural area (where i live), taking a 35mm to the park or beach, everyone look at me weird thinking I'm some sort of perv with 35mm SLR or DSLR( sorry for mentioning digital). But when I bust out my Rolleiflex or my 645, I can get away with most anything, less weird look from people. But there's a problem with my Mamiya 645 PRO with the long scope behind the Prism. Most of them would think I got a video camera, its better to take out the Power Drive and put the hand crank back on and let people know whats up. 35mm Range finder in a minor league ball park, 50/50, I'm invisible to some and some of them wanted to kick my ass. So far, i think medium format works the best, and my Rolleiflex T gets best reception and comments from people.
Bigger might be better, to clearly let peoples know " hey, I'm a photographer, not a perv. " After typing the last sentence, i can relate this to my old job, which requires lots of walking around in different neighbor hoods with a camera, taking photos of foreclosed houses that i was working in, either out in the boondocks or the hood, same difference really. The camera i was using is a point and shoot, to avoid getting shot by the neighbors literally, i wear a large "construction grade" reflective yellow jacket. Same idea with the medium format, stands right out, and let them know I'm there. Maybe someday I should put on my yellow jacket on with cameras, haha.