…A little further up the learning curve…
After a few days to think about what I learned in last week’s high speed flash challenge (see “Never say never high speed water drop challenge”), I decided that I needed a Mariotte bottle before having another try. The Mariotte bottle has an air inlet tube and a siphon tube. The distance between the bottom of the air inlet tube and the lower end of the siphon tube gives the “head” of liquid, which controls the exit pressure, enabling a constant rate of flow of the droplets, whilst allowing the exit pressure to be changed by increasing or decreasing the head (raising or lowering a tube). Stopping the air inlet will stop the flow of droplets (if air can’t get in, drops can’t get out) and avoids the liquid running away.
Once the Mariotte bottle was sorted, I needed to add some thickening to the water…I had taken delivery of some Xanthan gum with my Tesco order and put a teaspoonful into a large jug of warm water…it doesn’t like to dissolve but leaving it overnight does the trick.
The next morning I had a moderately gloopy colourless liquid which I could dilute to achieve a dropping consistency…after an initial test run, I diluted the Xanthan mixture further with a little milk. I had also taken delivery of some red food colouring, which I used to colour the liquid. The resulting slightly gloopy pinkish liquid formed perfectly spherical drops.
This time I did the sensible thing and placed a deep tray under the water dish, so I wasn’t worrying about it overflowing. Something else that helped this time was to use a remote flash trigger rather than a cable tethered to the camera.
I was now ready to go.
I felt a lot more in charge of what was happening this time and was able to control the flow of the drops much more accurately. It was still not accurate to the degree that you can achieve with a water drop machine, but for a simple DIY job, the Mariote bottle cost only pennies. If I was going to do this type of photography regularly, I would invest in a droplet machine…but will the fad quickly go away?