[smogcutter]

Your square color photos are almost certainly made from medium format film!

The most common frame size used in 120 is a 6x6cm square, especially in consumer cameras of the time. 6x6 cameras stayed popular for snapshots because they could be contact printed straight from the negative, without an enlarger. A whole roll of 120 can be contact printed onto a single sheet of paper and then cut. Much cheaper and faster than enlarging 35mm negatives.

With film there’s no such thing as a b&w specific camera. The difference you’re seeing is probably down to the glass in whatever cheap & cheerful 6x6 rangefinder they took those 1950s family snaps on, vs the photos from the AE-1 which is an all time great camera & lens system.