Today we have yet another death of a water balloon. In this particular situation, the balloon was in a gold fish bowl.

Materials
A goldfish bowl.
A water balloon, blue.

Observation
This is an interesting shot. Primarily because the water is contained and cannot escape in the normal manner by which water likes to escape. The water, not being aware that it was trapped in a goldfish bowl, still tries to escape to no avail. Having failed to notice that it failed to escape the water continues about its business of playing with gravity in a not entirely unpleasing manner. The bubbles are neat too.

Original Video

Today we have something a little different and a little special. Yesterday Rick Burmeister from MCT dropped by for a few hours to show me some of the new toys they have. We took a look at the new Photron SA-1 high-speed camera. Let me start by saying I was incredibly impressed with this camera. The image quality was wonderful in the two lighting situations we tested it in. The light sensitivity is really amazing. With these cameras you need as much light sensitivity as you can get, especially considering this camera will run at 5400fps at its full resolution of 1024×1024. This makes for a monster. Now on to the subject of the delay for todays post.

One of the really neat features that Rick showed me was the the ability to shift the visible bits from the 12bit image the SA-1 captures. What this allows you to do is adjust the brightness of the image, shifting to the darker bits allows you to capture detail that would have ordinarily blown out and shifting the other direction allows you to bring out the details that were in shadow and normally muddy. This is a useful feature when you are filming anything that has the potential to blow out to ranges that are normally incomprehensible, rocket engines, explosions etc. All while maintaining the other items in the scene. In the software you are only able to view and export these. This brings me to the topic of HDR (High Dynamic Range) Imaging. HDR is excellently defined (with samples) here. Unfortunately, the ability to capture motion with HDR was all but impossible with current digital high-speed cameras. The SA-1 opens the doors just a crack for us. After exporting three different versions of the same footage using the bit shifter, I started on the process of figuring out how to do this with video. After several hours of searching and experimenting I was unable to figure out how to get video sequences processed into a tone mapped image sequence. There were not any tools I could find that would make the process simple or even feasible so I contacted a few of my friends and started the process rolling to either find or make something that would do it. Chad Boyda was able to cobble together a basic setup that would allow for the batch processing of the thousands of frames the SA-1 kicks out through a HDR application, FDR Tools. The process we worked out is clunky, slow and results in a bit of strobe in the video, but the resulting image has far more detail than is normally available. Future versions of the tool should negate that strobe. Now just to disclaim, the source images are not precisely what one would get shooting with a bracketed f-stop so the process does not yield quite the same results, but it is closer than normal.

I’ve included the original video as well as three images that represent the three different videos that were processed to produce the final shown above.

Today we have yet another high-speed video of a water balloon serving its purpose in life.

Materials
A helium balloon filled with water
The standard fare of background materials.

Procedure
Instead of a vertical drop I thought a toss from the side would be interesting.

Result
I do so love it when water balloons distort themselves for our viewing pleasure. This one certainly did not disappoint in that regard. The water balloon can be seen undulating in a very odd fashion prior to its equally odd compression and explosion. The manner in which it hits the ground and compresses creates some very interesting shapes. In particular when it first hits and the top of the balloon (the first part to impact the ground) creates a shape that resembles the crown shape we see on water splashes. This is an excellent candidate for stepping through a frame at a time.

Today we have some more of that wonderful pearl swirl, only in a slightly different medium. I had a pan full of vinegar that I had used earlier in a baking soda shot, and then later had dropped lots of random colors into. That was used as the background for this shot.

Materials
Pan of white vinegar.
Several drops of green, red, brown and blue food coloring placed randomly around the pan.
A few drops of Pearl Swirl.

Procedure
Drop the fluid from a height of roughly 8″

Result
The Pearl Swirl and the colors really give these splashes an extra kick. The colors provide a nice back drop, in addition to emphasizing the waves. It is interesting to note how the Pearl Swirl appears to clump more in the vinegar than it does in water. That gives it a relatively grainy look as opposed to the normally smooth texture. As always watching the crown form and splash crater fill back in are always interesting. This time the addition of the silver of the uncolored Pearl Swirl adds an additional layer of visual complexity.

Lighting
The lighting rig used here is the same setup for the previous milk splash shots.

Fireworks are always fun. Well, with the exception of grievous bodily harm. Today we look at a spinning firework as well as some artifacting you may run into while filming with the Photron Ultima APX and how to avoid it.

Materials
A spinning firework of some kind. In this case I use a really cheap plastic shelled version.

Procedure
Set it in an open spot, light.

Result
The outside of the fuse is covered with a resin or epoxy that burns slower than the fuse it coats creating a simple propulsion device. The curvature of the fuse ensures that the firework spins in a specific manner. The sparks and smoke are both interesting to observe, as is the way the sparks illuminate the smoke as it passes.

Now let us look at the artifacting we see in the video. Specifically there is a carrying over of the brighter pixels on the right side of the screen to the left side. The pixels that are carried over also repeat across the screen in a regular interval. Another interesting artifact we see is the vertical banding on the smoke. I spoke with Nils over at Photron this afternoon in an attempt to figure out what was causing these issues.

After talking with Nils some more the problem was (as I originally thought) user error. The vertical banding is an issue that shows up when you haven’t calibrated the camera after moving to a new lighting condition. In this case I moved from indoors (bright) to the outdoors at night. You should calibrate the camera after doing any of the following; changing the lens, changing shutter speed or filming speed, changing the lighting. This will ensure you get a nice clean image. The repeating artifacting we believe is a lens issue but Nils is looking deeper into that problem. I have to say that I am really impressed with Photron’s technical support. The service has been incredibly fast and Nils was very knowledgeable and helpful. I have to commend Photron’s support, and when you are discussing a camera as expensive as this, good support is a must and they certainly nailed it. Well done Photron.

Today we have another high-speed video of a high viscosity fluid. We’ve had a similar shot on here several weeks ago but fluids are never the same and I absolutely love the visual quality of this particular fluid. I would like to take a moment to thank the Rival company for manufacturing it. Thanks guys, this stuff is neat. Tastes great too!

Materials
Rival Brand Cherry Snow Cone Syrup.
A small stainless steel pan.
Snow cone syrup application bottle.

Procedure
Fill the pan to the halfway point with syrup then use the application bottle to spray additional syrup into the pan.

Result
This shot is a excellent study of the dynamics involved in fluid interaction. The fluid is static before the first drop hits, after that the entire pan is in motion as the drops continue to fall. The crown formation and interruption of formation in this shot is particularly of interest to note. Also note the difference in the splashes that occur directly on the bottom of the pan as opposed to the splashes that occur in the syrup. Not only does it change the height of of the crown but it drastically alters the formation of the splash. As in our other shot with the same fluid, it is interesting to note the refraction (light bending) properties and how that affects the overall look of this shot. Personally I believe that is one of the prime contributors to what makes this shot so compelling.