Water Drop Musings
I have been shooting water drops for a while now.... since 2007. I still remember how excited I was when I got two water drops to collide with the first generation home made StopShot. I'd post an image of the controller but it was really, really ugly. No plans at that point to make it a commercial product - it didn't have a name at that point either. There were very few water drop photographers back then but I was inspired to give it a go by two high speed photographers, - Martin Waugh and Frans (footopa). I'm sure there were others but both of these gentlemen have been an inspiration to me and have had a huge influence on my work and even on the start of Cognisys. If you have not seen their work it is well worth the time to visit their sites.
Since then Cognisys Inc. was formed (2008) and StopShot was launched as a commercial product. Cognisys was the first company to offer an electronic water valve and controller that made capturing colliding water drop photography available to those without a technical background. We were also the first to offer a system that was capable of controlling multiple valves and flashes. Our products have evolved to keep up with the ever increasing expectations of our customers.
Since the early days there are now many additional very talented water drop photographers out there, much of their works puts mine to shame. I am however proud to have enabled some of their work as the vast majority are StopShot users. Some of these people include Hélène Caillaud, Markus Reugels, Daniel Nimmervoll, Jim Kramer, and Corrie White. I should note that all except Corrie are StopShot users.
by Martin Waugh
The Art of Drops
Most of the Water Drop How To pages on our website are on the mechanics and timing of getting water drops to collide. This page is going to be a bit different and focus on some of the subtleties of water drop photography. Most StopShot users can get an image of a colliding water drop within an hour of unpacking their new gear - some in much less time than that. Getting a capture of two colliding water drops is something that took me a whole lot of engineering and weeks to capture the first time. This page will have fewer numbers and more tips and tricks to get your water drop photography to the next level. Most of the items found here are things I have learned from customers or noticed through the years shooting water drop collisions.
Water - It's all the same... right?
Water chemistry an enormous part of creating some of the shapes seen in many water drop images. Thickening of the water with Guar Gum or Xanthumum gum is is the most common of water chemistry modifications. Either blend or boil 1 tsp of Guar gum with 1 liter of water and then filter to remove the unsightly particles in the mixture. This truly does make a significant difference in shapes that are possible.
I have had much better luck with soft city water over hard well water. Even if the hard water is thickened it seems to shatter on impact as opposed to flow into nice shapes. I have also seen other chemicals added to the mix like Jet Dri or glycerin. This also can make a very significant difference in shapes and watter behavior. Pick up Corrie Whites e-book for other suggestions and ratios of chemicals to add to your water drop mixture. I'll not divulge her secrets here but she does have some very good suggestions as well as some specific additives to try.
Super Tall Worthington Jets
The rebounding column of water that is formed after a drop falls into a pool is called the Worthington jet. Very tall jets make for some outstanding collision opportunities. The technique to get very tall drops took me a long time to figure out (much longer than I like to admit). The trick is to get two drops released from the valve one after another, Both released during the same long pulse from StopShot (40 to 60mS). They need to fall such that one drop hits just after the first, as shown in the image to the right. The two drops work together to make very tall Worthington jets. As long as the valve is plumb the jet will be straight and tall. If you notice it veering to one side or the other check to make certain the valve is plumb. Having a plumb valve is very important to creating repeatable results.
Measuring the Worthington Jet
The image to the right shows the type of collisions possible when you get a good tall jet to work with. This particular image was shot with StopShot using no sensor to detect the drops - everything was controller by timing alone. The water in the siphon was thickened with Guar gum according to the recipe above. It was also colored with blue food coloring. The cup being dropped into is four inches in diameter and about two and a half inches tall. It was filled to the brim with water. The image was lit with two Youngnuo flashes placed one on each side firing into a white curved background. The tape measure was held behind the cup just in front of the flash.
Notes About Lighting
So now you have these extraordinary looking sculptures being created out of water right before your eyes but you still are not happy with your images. Time to work on the lighting. Lighting water drops can be very challenging - after all water is clear - or lightly colored and it is very reflective making it excellent at creating specular highlights. Diffusion is a must. I have two favorite lighting configurations - both use two flashes. The first can be seen on our Three Valve How To page. The two flashes are behind the 1/4" sheet of diffused acrylic. The flashes are about 4" above the surface of the water. Their placement needs to be adjusted to give the most diffused and even light. This configuration gives nice diffuse light that creates a beautiful reflection of the drop in the pool. The second method I use frequently is to bounce the flash off the background. The flashes are even with the drop and pointed directly at the background. A plain white sheet of card stock works well for this, or even the back of a plastic for sale sign.
Stay tuned for more tips tricks and even some high speed video of water drop collisions.