A unique shot from New Zealand

We mature as photographers over many years, and we often look back on photographs we took in the past and lament how bad they are.  Some pictures, though, remain as favorites even decades later.  This is one such image for me.  I took this in 1981 on a black sand beach on New Zealand's south island.  It is iridescent ocean bubbles reflecting me as I leaned down to shoot them with a medium format camera -- the Mamiya RB 67.  I remember the shutter was quite slow -- 1/30th of a second -- and I used a 110mm lens which is roughly the equivalent of a 50mm lens in the full frame digital format that we use now.  One of the fond memories associated with this picture is that there was a dog on the beach who really wanted to play.  He would come charging over to me, stepping in my bubbles, hoping I'd throw a stick for him to catch.  I took the bait, but I threw the stick as far as I could so I'd have another 10 seconds or so to shoot.  It was very windy, and my eyes were tearing which made photographing tough.  My aperture was either f/4.5 or f/5.6 to gather as much light as possible. The shallow depth of field, though, meant that I had to keep the film plane as parallel as possible with the bubbles and the sand to insure I had enough focus. Back then the film we normally used for nature photography was either 50 or 100 ASA (ASA and ISO are the same).  I was using Fujichrome transparency film at the time.  I couldn't use a tripod because the waves and the bubbles kept changing.  I've always loved this shot, but it was a real challenge to take.