Maya pummeling test

<p>pummeling test from <a href=”http://vimeo.com/user491023″>Dennis Hlynsky</a> on <a href=”https://vimeo.com”>Vimeo</a&gt;.</p>

 

An attempt to create a battleground surface shaped by massive artillery fire.

In Autodesk Maya an Ncloth is created and hit with Nparticles. The idea was to create a slightly moving surface. Since the polygon surface used to make the Ncloth is being used as an attractor to shape the surface one could get similar results with a series of blend shapes. The advantage of using particles to strike the surface is the option of secondary particles controlled by the collisions.

There are three sections

The first does limits the restitution to the surface

The second allows the surface to “spring back” but would be a means of producing a series of blend shapes which could be used to keep the cratering.

The third sections is an attempt to use a texture map to modify the cloth attraction to the original poly topography.

 

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First recordings with the Edgertronic Camera – Tests

First off I want to say I am pushing this camera in terms of ISO. At the recommended ISO the camera noise is not an issue. All cameras with fast frame sample rates need light.. they take from f stops which results in shallow depth of focus. Since I require depth of focus I am pushing the ISO much higher than one might in situations where action is at a predictable distance from the camera and bright light is possible.

The Edgertronic cameras are great inexpensive cameras in the slow motion class. Priced out at around $5,000 these cameras do a very good job at a difficult task. The design criteria for these camera seems to be “a slow motion camera for the rest of us” When I say the rest of us I mean those of us who don’t have between 15 to 80 thousand dollars to drop on a camera.

Personally I like inexpensive cameras. One sacrifices a bit of quality for an oppressive overhead. Elimination of the overhead allows one a bit more freedom to respect the creative whim.

flight of a small brown moth from Dennis Hlynsky on Vimeo.

The quality/accessibility question is perpetual – How much quality does one sacrifice for the ability to do? What does an extra 60 thousand dollars buy? Do those dollars buy the edge one demands or does the monitory overhead prevent the actual doing.  At times this is a no brainer. Sometimes the loss of the obsessively fine edge is not significant. No one complained about those soft fuzzy video recordings of the moon landing. We use our cell phones to photograph and record video and live with rolling shutter and autoexposure.

Deciding when “good enough” is acceptable requires personal judgement.

If the lack of overhead allows one to record something truly wonderful then a scant bit of quality compromise is acceptable. But, its a fine line. It really depends upon intended use. A bit of noise is OK in scientific data collection as long as it doesn’t obscure anything significant – but not OK when inserting a slow-motion sequence into a finely crafted narrative film. One could use a low ISO and slower frame sample rate to record acceptable footage… but for the desire to stop a bumble bee wing.

The Edgertronic camera skirts this line. I immediately took to the Monochromatic version of the Edgertronic.  When I shared the first shots from the Monochromatic camera the comment most heard was “Wow … it’s so sharp! … Wow WOW!”

pollination from Dennis Hlynsky on Vimeo.

I did tint the image a bit but really… the camera does shine.

I was using an ISO of 600. I was shooting outside in the shade of a house on a cloudless day. So I wanted to try the color version…the ideal ISO is 100 but I needed the stops.

butterfly color test from Dennis Hlynsky on Vimeo.

Camera time: Thu Aug 7 18:14:35 2014
Sensitivity: 800 ISO
Shutter: 1/6000 Seconds
Frame Rate: 1000 Frames/Second
Horizontal: 976 Pixels
Vertical: 496 Pixels
Sub-sampling: Off sub-sample
Duration: 13.199 Seconds
Pre-trigger: 10 percent

Technically the differences between the cameras is an added color grid which reduces the capability of the color camera by 2 stops. Recording at high shutter speeds cuts down on the light entering the camera. I found I tried making up for the high shutter speed and two stops taken by the color grid by increasing ISO. At higher ISO the signal off the sensor is amplified and one gets more noise. Flashing is also evident. For data collection this a non issue … but it imposes itself on the narrative. The noise distracts from “reading” the story of the image. The standing noise is especially evident in the shadows… meaning the noise doesn’t move as the framing changes. This might be caused by the Bayer Grid and the extra large photon buckets of the sensor. Color noise in high ISO chemical film moves from frame to frame. Our eyes blend these consecutive changes into pointillist hues. This doesn’t happen with standing noise. The introduction of standing noise in Edgertronic recordings place another “visual layer” on the recording. Again lowering the ISO will minimize this issue.

The diminishing of two stops on the color camera for me becomes constraining. For the shooting I am doing I can’t bring extra light. I really need the depth of focus.

I’m asking a lot of a $5000 Slow Motion Camera. For scientific data collection I don’t believe it is a problem.  From the few testes I have done I have yet to determine the sweet spot between shutter speed, ISO and the minimizing of camera artifact. It feels like it gets worse with higher shutter speeds. Some flashing might be caused by the background of the shot. More tests are needed.

The “Pollination” example is shot with a fairly slow shutter with little artifact. These artifacts are clearly evident in the clip of the Smoke Ring.

Smoke Rings from Dennis Hlynsky on Vimeo.

Camera time: Tue Aug 5 15:23:52 2014
Sensitivity: 1600 ISO
Shutter: 1/2000 Seconds
Frame Rate: 1000 Frames/Second
Horizontal: 1088 Pixels
Vertical: 576 Pixels
Sub-sampling: Off sub-sample
Duration: 10.13 Seconds
Pre-trigger: 10 percent

Perhaps I should explain what I mean by the narrative of the image.

Often when a process is scaled (made faster, slower, bigger or smaller) the criteria for understanding what is going on shifts. We compare what we are seeing to what we have seen and deduce some information.  I call this knowledge a narrative. Narrative and story are not the same thing. One of the shifts in reading the image occurs when scaling the ratio of the recorded frame rate to the play back frame rate. For personal clarity I think of the recorded frame rate  as the image sample rate. Traditionally, this is referred to as “frame rate”. Using frame rate is confusing because the recorded frame rate and playback frame rate are not identical. One can record at 1000 frames per second and play back at 30. I found the term sample rate to be much more useful because it eliminates the confusion between recording and playback. “Sampling” always occurs while recording. Sample rate, playback frame rate, image quality, color, and sharpness influence our the sense we make of the image sequence. They play an important part in how we obtain narrative knowledge from the video.

In this next video the sample rate is 1000 images per second but the ratio of those frames to playback rate is manipulated. The video slides between slow-motion and realtime. Once can get a sense of something big in the first part of this video. Slowed motion can sometimes convey a lumbering giant… when fewer of the recorded samples are used and the narrative has shifted. the Hummingbird Moth appears nervously shaking the flower a little high on a sugar nectar rush.

As an artist I don’t want a the artifacts introduced by a camera to interfere with my intended narrative.

hummingbird moth 02 from Dennis Hlynsky on Vimeo.

Interface Notes

The new macbooks don’t have ethernet ports. I suppose one could convert a thunderbolt … shooting outdoors introduces a bunch of other design issues. The camera can be set with a computer through the HTML controller and disconnected to record independently. The “hummingbird moth 02” was shot handheld with the the camera disconnected from the computer. Some small computer… like a Rasberry Pi  with a small monitor would be all one would need as a camera controller.

The camera interface should have a brighter exit button. It is almost impossible to see in bright light using the Google browser. There are other interface issues. It would be nice to have a histogram. Even a readout of the value of the brightest pixel or zebra stripes would be helpful. Judging the visual exposure on the computer screen compared to the H264.mov is a bit disheartening. Often its very difficult to judge the whites. Since the standing noise is most evident in the shadows, my tendency was to let as much light in as possible to avoid the noise. My judgement of the live image as being properly exposed often resulted in the recording being too bright.

The camera rig for shooting in the pollination garden.

High Speed Camera Setup