The fundamental differences between them is that rhythm is associated with the movement of the eye across the picture (dynamic repetition), whereas pattern is static and is more linked to an area (static repetition). Many published examples of rhythms ask the eye to follow the rhythmical progression from left to right (should be easy enough .. I wonder what the Chinese make of this ..) and establish a cadence of rhythmical beat. Any form of anomaly that disturbs the rhythmical progression across the image can make the picture more interesting, especially if the interruption to the rhythm occurs to the right of the photograph after the eye has established its visual beat. Coming back to our old friend the Gestalt Law of Good Continuation again, and we can perhaps understand that the eye will extend its perception of the rhythm of an image beyond the borders imposed by the frame.Patterns on the other hand, are static, and have their greatest impact when they fill the frame and convince the viewer that they extend beyond it. Although still founded on repetition, this repetition is linked with an area and not a direction as occurs with rhythms.
I considered a number of options for this exercise, which required the production of just one photograph to illustrate each element. For pattern, I looked at some of the close ups from my visit to the RHS Gardens at Wisley, and especially liked this cactus as a representation of a pattern with its different sized, but very similar elements. There was also one other image from the London series which addressed ‘pattern’ very well – a series of windows which also fulfilled the criteria of extending beyond the edge of the frame and giving the impression of continuation. Oddly similar in colour and tone to the cacti too!
For rhythm, I selected one image from a series of photographs I took in London of the so called ‘Boris bikes’ which are available for public use for a credit card payment. I considered a number of angles for taking pictures of these bikes and also experimented with different focal lengths to test the impact of changing the depth of field on the visual impression of the row. I finally settled on this image which I took at 35mm and f/8 to encompass the whole row but allow the furthest bikes to fade out of focus. I think the figure at the end of the row adds a little to the photograph, but it is not as dominant a discontinuity as I had hoped for.
I enjoyed this exercise from the point of view that it provided a different challenge from seeking out basic shapes, and it was easy to find examples of patterns and rhythms, at least with architectural themes anyway. I was not successful in finding rhythms that contained a significant discontinuity to break the flow and for the eye to ‘find’ as it scanned across the image and I intend to continue to look for suitable pictures as I seek out further material for Elements of Design.