The multi-exposure function has been part of the Pentax DSLR feature set since the K20D, if I remember correctly. With this function 2-9 exposures can be combined into one file with auto-exposure compensation. On the K3 II and the K-1 the number is 2-2000, as far as I can tell, but even a measly 9 exposures can give interesting results. I have previously used this function to smooth water in normal daylight much like a long exposure will do in less light. I have also used it to reduce visible noise in night images.
This time I have used the multi-exposure function to take images of one single object from various standing points in order to create a more impressionistic image. It was a dull day with flat light, so I had to do something else to create an interesting image. All images below are based on 9 shutter actuations combined into one RAW file in camera:
#1
#1b - the same in colour:
#2
#3
#4
Personally I like #3 and #4 best for their graphic expression - almost like a rough charcoal image.