in Photography

Photography Tip: How To Get Smaller Scale Stop Motion

dice stop motion

One of the easiest ways to instantly make an otherwise normal shot into a compelling and dynamic image is to use stop motion. Take an item and freeze it in that moment of action. In the example above I needed a picture of a 20-sided die for the header of a dice store. Dice are relatively dull and uninteresting objects by themselves, so to spruce up the shot I captured the dice splashing into water.

Let’s take a look at how it’s done.

Your Shutter is Too Slow

The first thing to understand for stop motion of this kind is that your shutter is too slow to freeze the motion. Even the highest shutter speeds will not be able to stop motion as fast as the dice splashing into the water — liquid splashing moves fast.

Instead you need to use a flash to stop the motion — light moves much faster than your shutter ever could. This means that you’ll need to be in a relatively dim space: your shutter is going to be open too long and you don’t want to expose anything except for the instant that the flash is triggered. You’ll need to set your DSLR to its highest sync speed (the highest shutter speed at which it will reliably be fully open when the flash triggers) and set it on fully manual mode. You will have to focus ahead of time, as well as setting your exposure. I’ve found trial and error to be the easiest way to set the exposure, which is incredibly easy in today’s age of digital photography. Just be sure to check your histogram on your display as you’re drilling into your exposure.

A Note on Focus: if your camera is pointing downward, as mine was in these dice shots, and you’re using a zoom lens, be aware that your lens will gradually drop out of focus. This is because the force of gravity on your lens is slowly dragging it down into a different focal length. Truly high end lenses can resist this (but they cost a fortune) and fixed focal length lenses usually don’t have that issue, depending on how the focus works, but in my case I just had to refocus every few shots.

Flash vs. Strobes

Most photographers have a flash of some kind laying around, but if you work with lighting at all you probably have strobes. Strobes are a fantastic bit of equipment for lighting; however, they will not work for lighting your stop motion. Had I used my strobes for these shots I’d have ended with blurred dice and blurred water.

The problem comes with the duration of the flash. Strobes have a very long duration of light — so long that your motion will get blurred. A typically strobe has a T0.1 duration of around 1/300th of a second. There are two ways of measuring flash duration:

  • T0.5: this is the length of time that the flash is at 50% brightness or more. This is the shorter way of measuring and is what strobe manufacturers usually proudly report. This is not a useful measure.
  • T0.1: this is the length of time that the flash is at 10% brightness or more, and it’s usually about 3 times as long as the T0.5! This is the measure that’s important for stopping motion.

While most strobes are hanging out at a slow 1/300th duration or worse, flash heads are much, much faster. A typically flash head will have a flash duration of 1/1000th to 1/10,000th — this is what we need to freeze those dice just as they’re hitting the water!

dice splashing into water

Timing

For the shots of of the dice dropping into the water I just used a glass cooking dish. I set a black t-shirt in it and then filled it with water. I needed a pure black background to match the placement of the photo online, but if I wanted to see more of the water I could have used a lighter background, or even had light coming in the side of the dish.

One of the tricky things about trying to do stop motion photography like this is timing. When you’re trying to get the shot at just the right instant, human reflexes perform pretty poorly. I’ve only found two ways of handling this: the hard way and the high tech way. I’ve done them both, they both work. The hard way just takes more time.

  • The Hard Way: the hard way is to manually trigger the flash. Typically the way you’d do this for the dice shot would be to drop the dice then try to trigger the flash just as the dice hit the water. Most of the time you’ll miss, but sometimes you’ll nail it. One of the interesting things I’ve learned is that it’s much, much easier to time if you’re the one doing both the dropping and triggering the flash. Somehow it’s instinctively much easier to time it than to watch someone drop, even with a countdown.
  • The High Tech Way: this is the way I did it with the dice shots. I had a simple audio circuit to automatically trip the flash when it heard a loud enough sound. I set a tiny microphone next to the dish of water, and the sound of the dice hitting the water instantly triggered the flash. The setup I used has an adjustable delay, so I could easily experiment and find just the right instant of triggering the flash time after time. Of course dropping the dice in just the right spot, and getting the right numbers to show was a matter of a lot of trial and error, but at least I didn’t need to worry about the flash.

Put it All Together

That’s all there is to stopping motion on a small scale. It’s worth noting that it’s much, much easier to stop motion on a small object like these dice, or water drops falling, than for larger objects. The primary difficulty with large objects is the sheer amount of light you need to illuminate a large area.

For the dice photos I used just one flash set at about a 45 degree angle next to the camera with a reflector on the other side (you can use your built in, but you’ll tend to get flat pictures if the lighting is coming from the same angle as the camera). This technique works great for dropping things in water, or pouring water onto things.

Once you move into really precise timing situations — like shooting things — you will need some kind of automatic flash trigger. You just aren’t going to be able to time that manually. But any kind of dropping, pouring, or even bursting a water balloon you’ll be able to handle manually through some trial and error.

Brian Wood is freelance product photographer and blogger, and recently did the product photography for Awesome Dice Online, including the dice splashing shots featured here. You can follow him on Twitter at @awesomedice.

Bogdan

Bogdan is the founder of Top Design Magazine. You can find him in Bucharest-Romania so next time you want to drink a beer there and talk about web and stuff, give him a message.

Leave a Reply