A diptych is a combination of two images placed immediately next to each other to make an artistic statement or comparison. The photographs can be identical or they can be different; there are no hard and fast rules – they simply have to be next to each other.
When I bought the Kodak H35 Ektar half frame point and shoot it wasn’t so much with the idea of saving money by getting two exposures on a normal 35mm frame, although there is that to think about. It was actually to see if one could actually get a diptych in camera. It’s a bit of hit or miss to get two similar subjects next to each other AND in the same vertical vs. horizontal orientation. The examples here were shot relatively randomly.