Worthington jet from a first droplet impact collides with a second droplet

Worthington jet from a first droplet impact collides with a second droplet

By Stephanie Mora for Get Wet 2016

A Worthington jet is formed when a droplet falls with enough velocity on a liquid surface (Inglis-Arkell 2015). The droplet creates a crater in the liquid surface and from the center of that crater protrudes a central jet and with enough energy the jet will pinch off and send more droplets upward (Inglis-Arkell 2015). This is the main phenomena I was trying to capture in my Get Wet image, but on top of that, I wanted to capture another droplet hitting that Jet and creating a crown. I was only able to capture as good of an image as I did thanks to an apparatus created by Kyle Walters and Kyle Hollis and a Bluetooth app called dropControllerBT designed by Martyn Currey.

The apparatus they built stood on two metal legs and could have up to three horizontal bars attached between the legs. On any one of the horizontal bars (preferably the highest one) you could then attach 3 liquid containers, each having a tube connected to a dripper. The drippers would be fixed on one of the 2 lower bars. Positioned below the apparatus was a basin of water, approximately a foot and a half in length, 8 inches wide and 4 inches deep. Directly in front of the apparatus was a camera on a tripod which was connected to a circuit box also built by Kyle and Kyle. The circuit box was connected to the drippers and two flashes that were placed on the left and right side of the basin. Everything connected to the circuit box was controlled by the dropControllerBT app. The app allows you to control the opening of each valve, drop start time (in milliseconds), size of drop (controlled by how long valve is open), time in ms when the flash will go off, and the time in ms when the camera will go off (Currey 2016). All of these settings could be customized differently for each valve.

In our trials we noticed that tilting the valves at an angle seemed to cause the Worthington Jet to come back up at an angle. When the second droplet was dropped it hit the middle of the jet as opposed to the top, creating a crown over the middle of it. Through the crown you can still see the jet and how it extends taller than the crown. On the tips of the crown you can see where droplets are being pinched off and extending outward.

In order to bring emphasis and aesthetic appeal to the droplet, we used purple food dye for the droplets. The basin of water did not have any dye in it. To control light we had two external flashes with just white light. In other trials, we had put red and blue filters on each flash, but for this image, the flash did not have a filter. In the room we were in, we had the normal ceiling lights on as well.

Because I did not have the proper cable to connect my small Canon PowerShot SX260 HS to the circuit box, I used their Nikon D700. The camera was placed about 7 inches from the basin, positioned so you could not see any borders of the basin, just the pool of water. We exclusively relied on external flash and lighting. The f-stop used was f/22, an ISO of 400 with a ½ second exposure and the focal length was 105 mm. As I mentioned earlier, these settings produced an image that was too bright and looked a bit washed, especially the purple. This was not our intention, we were playing around with settings and this happened to be the set that actually captured a beautiful drop collision. To add vibrancy back to the photo, I used Gimp to increase contrast and used the burn tool around the droplet collision to bring out the purple. I also cropped the photo to make the focus more central on the droplet collision and remove other distracting boundaries. From previous trials, there were a few droplets on the stuck on the backdrop, which I removed using the clone tool.

My favorite part about this image is the aesthetics of the drop collision. Also, how the crown is transparent and the jet below can be seen. I love the contrast of the purple with the black and white surrounding it. I also love the contrast between the calm ripples and the crown that is spreading out in different directions. I believe that the physics are very well and clearly shown in this image. Neither I, nor the two Kyles understood exactly why the drop was coming up at an angle, because even when we did straighten the angle of the valve, it still came up at a left tilted angle. But this ended up working in our favor. As a non-engineering student, the only improvements I could think of would be incorporating more colors. I would want to drop different colors onto each other and try to capture the blending of those dyes in the droplets. Another idea I would want to do would be having multiple droplets fall side by side, in different colors, and then try to capture 2 or 3 droplet collisions at the same time. The precise controls allowed by the app we used would make it possible to capture such an image.


Currey, M. (n.d.). DropController Bluetooth. Retrieved September 26, 2016, from http://www.dropcontroller.com/dropcontrollerbt/


Inglis-Arkell, E. (2015, June 11). A Rare Look Inside The Formation Of A “Worthington Jet” Of Water. Retrieved September 26, 2016, from http://io9.gizmodo.com/a-rare-look-inside-the-formation-of-a-worthington-jet-1710712711



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22 Comments. Leave new

  • This is probably my favorite picture. This is awesome! Very artistic, nice representation of flow, flawless photographic technique. I have no constructive criticism, this picture is perfect to me.

  • 1. Artisitic intent is displayed well.
    2. The flow physics are revealed well.
    3. The photographic technique has sharp focus and is well done.

  • This photo is awesome with the cool colors and reflection of the jet on the water. The image is perfectly in focus, and there are no distractions in the foreground or background–good framing and post-processing

  • Preston Marcoux
    September 19, 2016 3:55 pm

    The image does a fantastic job capturing the collision, your focus is great. What really makes the image pop is the unique shades of purple that was captured. Beautiful

  • Alexander Thompson
    September 18, 2016 10:29 pm

    This an incredible piece of work! I love the color, it adds so much visual appeal to an already stunning image. The timing and focus are truly amazing to capture such an impressive shot of a droplet hitting a Worthington Jet. Great work!

  • This is my favorite photo in the gallery great work! The lighting and focus were perfect. Keep up the great work!

  • Joseph Straccia
    September 16, 2016 5:37 pm

    Excellent photo. The focus is just right. I find the purple color pleasing and enjoy the texture and patterns of the ripples in the tank. There are some interesting optical effects going on here between the reflections off the liquid in the tank and the transparency of the sheet of purple water from the impact.

  • Maxfield Scrimgeour
    September 16, 2016 12:28 pm

    Great use of the droplet tool to capture such a mesmerizing photo. I really like how the top droplet seems to stretch over the other one as they collide. Good use of food coloring to give some more contrast to the photo

  • I like the contrast between the background, water, and dyed water. I like how detailed the flow is and how sharp the image is. The photo is aesthetic.

  • Your color choice of food coloring and background creates a very clean and minimalist canvas. I like the detail and precision of this image. It’s very stunning work.

  • 1. This is one of the best!!
    2. The light looks amazing
    3. The surface is interesting because it provides a good contrast to the purple

  • Highly complex flow.
    I really like the extra effort taken with the apparatus
    Top notch

  • My personal favorite photo. This photo is so crisp and the contrast is so cool. Being able to see through the layer of water is amazing. I don’t see any evidence of a “double exposure” or anything like that. AMAZING photo.

  • This worthington jet is beautiful. It properly displays the physics behind the fluid flow and the purple color brings out contrast. Definitely aesthetically pleasing.

  • Alexander Rosenberry
    September 16, 2016 12:16 pm

    Stunning photo! The sharpness of the drop collision is almost surreal. I am super impressed by how the whole splash is in focus. The lighting effects are very nice, and this pictures has an extremely professional feel.

  • – Great photo and use of color for worthington jet.
    – The picture looks very clean against the background.
    – Good use of apparatus makes a nice effect of colliding water droplets.

  • -Beautiful capture of food coloring before mixing
    -Clearly illustrates phenomena with perfect timing
    -Perfectly focused and very sharp image

  • Michael Waterhouse
    September 16, 2016 12:15 pm

    Art: Beautiful color. No distracting elements. Flow: Lots of detail in the flow. Publishable quality. Photographic Technique: Good lighting. Background is not distracting.

  • Art: The color contrast between the background and the water droplets are great.
    Flow: The flow is quickly understandable and recognized.
    Photographic technique: The focus of the water is fantastic.

  • Wonderfully crisp worthington jet, and interesting scene with collision of the jet. Nice non-distracting background and coloring of the image.

  • Art: The uniqueness of the purple fluid sets this apart
    Flow: Worthington Jet is a beautiful effect
    Photography: Great lighting and shadowing

  • Sierra Castillo
    September 16, 2016 12:15 pm

    Great image capture. The light is not distracting. I like how the purple brings the eye exactly where it needs to be. I also like how the rest of the image is very focused and sharp. Very interesting photograph.


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