I often get requests for information about techniques. Here is the “stock reply” that I have been using to save me some time. Now I can just point people to this post!
I don’t use special cameras or lenses, really. I am currently using a Canon 5D and a 180mm macro lens, but other equipment works, too.
I use fairly typical high-speed photography techniques.
I leave the shutter open for a relatively long time (in a darkened room) and use a flash to illuminate the splash. The flash needs to be of a fairly short duration to stop the motion well. I use something like a 50 microsecond flash. “Speedlite” flashes (as opposed to studio strobes), control the amount light output by varying the flash duration. Not surprisingly, the shorter the duration, the less light (many studio strobes are the opposite!). So, you can get a short duration by setting the flash for low power (1/16 or 1/64). I get this by modifying the photo sensor circuit on Vivitar 285HV flash (a bit more detail) .
Timing the flash is done with a photogate and electronic timer. www.hiviz.com has techniques, equipment diagrams, and kits.
I have built my own timing and triggering devices (a few different ones, as I learned how to do it better.) My advice is: if you want an electronics project that will take a lot of your time (unless you’re already an EE), then design and build your own. If you want to take pictures instead, purchase the equipment. Here are some vendor choices: www.bmumford.com, www.woodselec.com, www.universaltimer.com, and www.cognisys-inc.com. And Make magazine has a kit: www.makezine.com/flashkit and www.quaketronics.com/flashkit.
It’s hard to give a single formula for lighting, since different situations lend themselves to different approaches, however, using an on-camera flash is not an arrangement that I prefer, especially for the clear liquids. Rather, I use remote flashes in various locations. In the end, lighting these shots is no different from any other similar material. The only difference is that I use a flash with a short duration to stop the motion. So, for clear liquids I use the same techniques as I would for glass, since they behave optically much the same. For an opaque liquid, like milk, I light it as I would for a white bowl (except smaller, of course.) A good book on lighting is “Light: Science and Magic”.
You will wrestle with depth of field issues. There are a few things you can do to help, but they all have their downsides.
The photography is in many ways the easier part of what I do. Handling the fluids is what takes the creativity and patience.
I have developed a fairly complex system of computer programs and hardware and mechanics that I use to create drops and do the timing. Still, I take a lot pictures and make a lot of mistakes. I have a post that goes into more detail on this, too.
A simple setup is described in www.dpchallenge.com.
Andrew Davidhazy, at the Rochester Institute of Technology, has good information on high-speed techniques, as well as other fascinating types of photography.
Fotoopa.com has some creative techniques.
Harold “Doc” Edgerton, of course, is the father of the xenon flash tube and high-speed photography. Search for his books on Amazon.com.