I like this one for how vague it is, but dislike it for not getting the detail that I wanted while still having too much. Do I sound neurotic, or just spastic?
But okay, the explanation. First off, this is winter 2015, and shows something that I heard about and always wanted to try, but we rarely get the necessary conditions at this latitude. You’re seeing a soap bubble in the process of freezing over and becoming solid, because it was about -8°c outside, plus the soap solution had been pre-chilled. It takes temperatures this cold because the soap bubbles will typically pop on their own if you have to wait longer for them to freeze, so it has to be pretty quick, and seriously, you can often watch the ice spread across the surface; I did not have video capability at that time, otherwise I would have been attempting that.
But the other aspect is getting it distinctly visible, which takes a dark background and light at just the right angle, which I largely accomplished here. The flash unit was off-camera to the side on a light stand, connected to the camera by a coiled cord, and that’s the dotted line you see under the rainbow edge of the developing frost, since it caught the light from the flash. It can take a lot of playing around to set everything up right, not including the soap bubbles that pop too quickly or start freezing on the back side. I just had to go back through the images to check: it was about 90 minutes of shooting for the first session, where I worked out a lot of the kinks, but only 15 minutes for the subsequent when I caught this – I think everything was still set up then, though the temperature had dropped further and I was having a little better luck then.
A bit of trivia. While I thought the rainbow effect was caused by refraction, it’s not – it’s actually light wave interference from the light reflecting off of both the outer and the inner surfaces of the soap membrane, separated by that fraction of a millimeter that causes the waves to go out of sync, doubling up some colors and canceling out others. You can even see the colors swirl due to the thickness of the bubble shifting as gravity pulls the soap around. I mean, not when it’s frozen, but normally.
I’ve tried this freezing bubble trick twice since, I think, and never got anything decent, and as I said, we rarely hit those temperatures here, so I get the chance once every couple of years, if I’m available and motivated at, you know, two o’clock in the morning…