Analog film photography and cameras

Also the rangefinder (and rangefinder 'style')cameras often have the viewfinder stuck right atthe edge of the body, when you use it it block your face much lessly than an slr so if you talk to your subject etc it's less inbetween you.

One can also quickly zone focus and use a clip on sportsfinder (such as the Ikondot) to reduce the barrier even more.. One can also use a Voigtlander Kontur finder and keep both eyes open--- it works really well (there was also a British copy but the name escapes me this moment,... started with the letter K... something like Kerin).
Lastly... Rangefinder objectives can be quite small.. much smaller than those made for SLRs.. People often just see the big lens barrels on SLRs and react..