High Speed Photography - Liquid Droplets

Hello, my name is Kev and I am the photographer behind KpHfashion. Is blogging something you are comfortable with? Or are you more familiar with a good old fashioned manual? or do you regularly watch "How did they do that" kind of programmes on TV? Well consider this page something similar, it has been created to explain how I achieved the image below called "Magic Milk Mushroom Picker." It uses a well known method of capturing droplets so I cannot claim to be the godfather of a new art form nor the innovator in technical wizardry. I have simply used what is out there. You may or may not like the actual image, which is not necessarily important, but it serves as a baseline for me to explain what I did and hopefully inspire you to try something like it yourself. Enjoy!

 

Having read this far you now have a choice. You may be thinking that you know all about droplet shots, in which case I won't be offended if you change to another channel. You maybe thinking I know how high speed photography is done but I want to know about the photoshop work on this particular image - then jump straight down to the Post Processing section. But if you don't know much about this type of photography then stay tuned.......

 

 

 

 

 

 

Liquid Droplets - MytAkeoNit

I do tend to think and study something first before snapping away, especilally when new subject shapes or lighting scenarios turn up. So when I first saw high speed photography shots, about 30 years ago, I thought wow....but didn't do much about it. Mainly because it was done in University labs with very expensive and highly modified strobes. So fast forward....to about 2007 I saw the later equivalent of those high speed shots but this time with water droplets as the subject and the lighting equipment was much less esoteric. I had thought about this long enough, began to play around with drops of water and quickly found three common problems. Firstly, if you look around for droplet iimages they do all seem to be quite similar. Essentially a very strange shape set against great lighting and reflections perhaps linked to a prop such as a cup. Secondly, my attempts at freezing the action were simply not sharp enough. The third problem is getting the drops consistent.

My take on it is that these wonderful moments in time, however brief, need to be captured and used together with the people photography that I normally shoot. I wanted to use the droplet shots as an integral part of images rather than the sole subject. So in theory, getting something a llittle bit different or unique may not be such a problem. That as a concept is great but we need to get over problem two and three above.

I guess I went through the well traversed, non-educated, experimental path of discovery, quickly realising that I was using my kit in the wrong way. My camera, an offensively expensive Nikon was useless even at the fastest shutter speed it can muster. I did have some Vivitar 383 flashguns with manual override and set about reading the manual to see exactly how fast they are. At the time the characteristics of a flashgun or studio strobe was a revelation to me. But strangely, knowing what I know now, it should have been obvious. I have appaling eyesight but 20/20 hindsight.

 

 

 

 

 

 

 

 

Technical Stuff

Be under no illusions, this type of photography gets a bit technical, throwing money and gadgets at it gets you more consistent and reliable results. Having learnt the hard way, realising that the trick is to keep the shutter open and use the flash to freeze the action, I now had the problem of firing the flash at the subsecond instant that I wanted. And to do that repeatedly.

There are a number of side issues with flashes and strobes like the fact that the flash itself builds up to its maximuum and then dies away. Much like what you see when you turn a car headlight on and off. The flash does the same albeit much much faster. Also, the temperature of the light (colour balance) is also variable during its lifecycle. But of course what you and the camera see, in a fraction of a blink of an eye, is just a blast of light. Fascinating stuff.

I digress, back to the Vivitar 383s. These are cheap workhorses but do have a flash duration, and by that I mean that light is being emitted, for a very short amount of time, something like 1/20000th of a second. That is four times faster than a good camera shutter. The measurement of 1/20000th was against one of my ageing units so not sure if it was in tiptop condition. Some forums suggest they should get to 1/30000th of a second. But one key element is that to reach these super fast speeds, the flashgun needs to be at its' lowest power setting. If the flashgun is automatic then it must be placed close to the subject and ensured to get a blast of light back at it so that the sensor shuts off the flash straight away. Or, better still, put the flashgun in manual and set it to it's lowest power setting.

So to the main issue of timing, after much trial and error, browsing the Internet I eventually bought a technical solution in the form of Cognisys StopShot. This gadget allows you to control the droplet of liquid by firing a valve to release a drop then firing the flash automatically afetr a defined period of micro seonds.

My shots were still not pin sharp though, perhaps I was being a little too choosy, after all there are many droplet images on the web taken using the Vivitar 283. I decided to try my Nikon SB600s and SB800. The official specifications suggest that at their lowest power settings their flash durations are 1/25000th and 1/41600th of a second. That I thought should be fast enough to capture a droplet perfectly. Well at 1/25000th I was not completely satisfied so went with the SB800. I believe that the equivalent Canon flashgun has similar flash duration so Canon users are provided for.

 

1. There is much technical documentation online, especially at the Cognisys website which was extremely useful but here I will show you my setup. In the first setup picture you can see we have a siphon (the cylindrical thing) which holds the liquid that is about to drop. Attached to the bottom of the siphon is a valve which allows the liquid to be dropped in a very precise manner. The amount of liquid to drop and when the drop is let go, is controlled by the clever device called the StopShot .
2. When a drop is released, the StopShot box of tricks sets a timer going when the droplet passes the infrared sensor.
3. The StopShot is then used to automatically fire the flash at a number of micro seconds after the droplet passes the sensor. Hence the consistency.

 

 

Despite the fact that this is an expensive and very accurate piece of kit, there are so many factors that vary the behaviour of the droplet and subsequent splash, that each collision is unique. We have the chaos theory, the butterflys in Brazil, the depth of the target liquid, the height that the droplet starts, the size of the droplet, the actual liquid that is being dropped and the liquid density that is being hit...just to mention a few. So if you are thinking you have seen it before and nothing is new, explore the world of droplets.

 

 

 

 

 

 

 

 

 

 

 

 

Once up and running I had reasonable success fairly quickly, creating some still life shots called 'Lighthouse' and 'Evolution' then introduced the droplet shot into a shot with a model. During 2010 I was then distracted until come December I suddenly got a burning desire, more like a burning image in my mind which would just not rest.

 

 

The Idea

Some of the droplet shapes I was seeing were very reminiscent of mushrooms, Therefore I thought, it would be a good shot to get a bunch of them together to look like a patch of mushrooms. Of course I could not get a whole bunch to form naturally even with this high tech kit, so I was relying on a high degree of Post Processing in Photoshop, which I will come onto later. However, I was not satisfied with any old bunch of mushrooms. As I had set out to do, I wanted it to be different and with some form of reality built in, hence the hand picking a mushroom. The idea was set - almost instantaneously - whilst in the bathroom.

The liquid in the plastic tray was milk to give it that mushroom stalk smoothness, the tray was filled to the brim so I could get the camera at a low angle to the splash. The liquid in the siphon was water mixed with Baileys Coffee Liquor. The idea was to ensure that the tops of the collisions were darker and more colourful than the stalks. What you see in these images are not single splashes, but two drops. the first droplet bounces against the surface and creates the rising column, sometimes with a bulbourous head. The second droplet, again controlled by the StopShot, is following micro seconds later and if you are lucky, hits the column as it is rising. In the final image you can see where the water(blueish) and the Baileys(Whiteish/Brown) are causing swirls for a great effect.

Post Process

Knowing that I was due to spend some time post processing, the images that I had captured (example below) were all shot with camera on tripod at a shutter speed of 1.5 seconds and aperture of F32. The ambient light was very dim, just enough for me to see what I was doing. The shutter speed and aperture were chosen because I wanted to make sure I could remove all ambient light but also I needed the shutter speed to be long enough for me to activate the StopShot to cause a droplet and splash before the shutter closed 1.5 seconds later. Aperture F32 was used because the camera was on macro about 6 inches from the drop point. I needed to ensure that minimal depth of field blurring occurred because it would have looked wrong in the final merged image.

 

 

 

 

 

 

 

To grab enough stock images at various angles I was shooting, transferring, adjusting for about 8-9 hours, with a dinner break of course! This included about 40minutes to create a prototype image in Photoshop so that I new I could get to the image that so vividly hit me in the bathroom. The following day, I spent around an hour in Lightroom and Photoshop culling the images till I got to the ones I knew I wanted to use. That was followed by about 2 to 3 hours masking, layering and fine tuning the final image. I had specifically set out to create a black and white image, hence the choice of colours, background and liquids but I do equally like the colour version below.

.Enjoy!