Author Topic: Opportunistic test: Bullet Time with the Z8  (Read 457 times)

Øivind Tøien

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Opportunistic test: Bullet Time with the Z8
« on: September 21, 2024, 11:30:23 »
When my friend invited me to come along for his mandatory annual target practice at a shooting range before the Norwegian moose (“elg“) hunt, I got the idea to test how difficult it would be to catch a bullet in flight leaving the barrel! We all remember the news image of a bullet streaking past a presidential candidate whose name is not be mentioned, so how much luck was involved in that shot, assuming the photographer was shooting in some high speed mode?

My initial thought was that it would be easy using pre-capture on the Z8 (I initially used 1 sec, but soon reduced it to 0.5 sec). I decided to try 60 and 120 fps, but used more of the former that dictates DX mode as I was uncertain of the resolution at the120fps full frame mode. However with a short shutter speed, for instance with 1/4000s I soon realized that there is only 1.5% statistical chance to catch the bullet in the frame if it passes within that 1/60s interval. A longer shutter speed would increase the chance of capture, but with the poor lighting that was at the roofed shooting booths and dark rainy weather, the trace could become very weak. I tried shutter speeds from 1/500 to 1/5000s, but mostly above 1/1000 sec. I also had to aim from an angle safely behind my friend, so depth of field was also an issue. I used focal lengths from 30mm to 300mm, but most with the 105mm f/2.5 AIS.

The hunters are first to make 30 practice shots on a regular target on two different days, after which they had to pass a test where all 5 shots on a game animal profile were within a 30cm circle at 100m distance. This is to make sure of proficiently of the hunters to perform as humane and fast kill as possible. 

Result: The pre-capture would catch the mussel flames or the smoke (most guns had silencers) from every shot without problem. By comparing the smoky capture with the two frames before it, it was easy to detect presence of bullets. While these are not fantastic from a photographic standpoint, from a total of 43 gun shots (most of them by my friend) and 7340 frames, I captured at least 8 confirmed bullets leaving the barrel - much better than expected from the statistics!

#1 Mussel flame without silencer, no bullet.
#2 Wide shot at 1/1000s with a streaking bullet hardly visible far away against the dark field (red circle), some smoke already appearing from the barrel.
#3-6 Bullets in red circles, shutter speeds #3: 1/2000s, #4-6: 1/4000s.
#7 Animation of 7 frames from one of the bullet shots above.
#8 Cropped animation of #2.
Øivind Tøien

ColinM

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Re: Opportunistic test: Bullet Time with the Z8
« Reply #1 on: September 21, 2024, 15:28:45 »
Fascinating experiment Øivind.

For me, the first animated photo demonstrates this the most clearly.

Given the constraints you had (inc poor natural light) I'm wondering if either of these would help
- flash (though some experimentation required)
- good side illumination from a bright LED torch, headtorch etc a metre or so away from the marksman?

The bullet which you captured passing through the beam would show up with better contrast....maybe?

Øivind Tøien

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Re: Opportunistic test: Bullet Time with the Z8
« Reply #2 on: September 21, 2024, 22:03:31 »

Thanks for the comment Colin. These are good ideas if one were able to stage a shot. Being out in the sun allowing reflections from the bullet would potentially also help (was probably the case of that famous press photo, otherwise such a long trace at slow shutter speed would likely not have been so visible). There were shooters at every booth, and I was only just allowed to be there, so I think anything more intrusive that could potentially be a distraction would have been a no-go. In a staged setup being able to capture more from the side of the barrel would also have helped to have more focus on the bullet, although there are always safety concerns to consider.
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Akira

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Re: Opportunistic test: Bullet Time with the Z8
« Reply #3 on: September 21, 2024, 22:09:59 »
Very intriguing experiment to reveal a rather esoteric side of a still camera.

The most challenging aspect of this experiment would be the way-too-shallow depth of field at this shooting angle (yeah, both the camera and the rile!).  Nevertheless, the result should be enjoyable enough.

Not to compare, these videos of the YouTube channel should interest you  :)

https://www.youtube.com/watch?v=cQ9jA9Fa914

https://www.youtube.com/watch?v=8kK8kXP1h1A
"The eye is blind if the mind is absent." - Confucius

"Limitation is inspiration." - Akira

Øivind Tøien

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Re: Opportunistic test: Bullet Time with the Z8
« Reply #4 on: September 21, 2024, 22:23:58 »

Thanks for the comment and link Akira - very interesting and also shows how one could be better off with a more favorable shooting angle in a staged shot. Wow 875,000 FPS!
Øivind Tøien