Oil And Water; Who Says They Don’t Mix?:
I used a 50mm macro lens plus one extension tube for most of my shots, although when I wanted to frame more of the surface of the water I took the extension tube off and simply used the 50mm macro. I assumed at first that I needed extensive depth of field, so I set the camera to Manual Exposure mode, set the flash to ETTL, and chose f/16 as the lens aperture. My rationale was to make sure I had enough depth of field over the surface of the water. However, what I discovered was that the small lens aperture made the paint on the paper too defined. I wanted the colors to softly blend together in such a way that the lines and the design of the paint on the paper didn’t show at all. A blur of color was the type of background I felt would be ideal.
Therefore, I opened the lens to f/8 and that gave me exactly what I wanted. I hand held the camera to take these images, but I was careful to make sure the back of the camera was as parallel as possible to the surface of the water. This gave me the depth of field I needed for the oil and water. All of the points on the water’s surface were equidistant to the digital sensor, thus depth of field wasn’t an issue, and the colored background was completely out of focus (#3 and #4).
Variation On A Theme
After I took quite a few pictures, I experimented by pointing the flash up through the glass from about 2 ft away and took a shot of the bubbles. I was amazed by the space-like images the circles of oil made (#5). It was like I was in the middle of a crowded solar system with dozens of planets. I made no exposure adjustments—I simply shot straight into the flash. The extreme contrast added to the extraterrestrial-like environment. Likewise, though you have to be extra careful, you could shine a regular light up through the bowl as well.