The first step in the setup involves pouring a layer of water into your clear dish. How much depends on what you would like to photograph and the effect you would like to create.
If you use a small amount of water, scratches and markings on the dish you are using will be visible through the oil and water. This can actually look quite interesting.
As oil is less dense than water, causing it to float, using more water creates distance between the oil bubbles and the bottom of the dish. Adding more water will make any markings in the dish become background blur and are less visible.
Next, add your oil of choice. The amount can vary. I recommend you pour a little in, observe, and then add more as you see fit. I usually start with about a teaspoon.
I have used a pump-and-spray bottle to create very small bubbles of oil across the water. I have also just poured some oil in and used a skewer to stir the oil until I get oil bubbles the size that I am interested in.
When first added to the water, the oil will have a “flat” appearance when you photograph it. By stirring the up the liquids, you give the oil bubbles a more three-dimensional appearance.
A drop of dish soap can have the same effect, while also giving the oil bubbles a rounder appearance, with thicker-looking walls.
Next, you will want to place your background underneath the dish. Whether you are using wrapping paper, a colorful scarf, or some other material, be sure that it is directly below the oil and water that you will be photographing. I start at a distance of about 30cm (12inches) and raise or lower the background for effect.
ISO 3200
f/5
SS 1/160 sec