stroboscopy

4 Articles

A drill bit, not apparently rotating, descends toward a block of aluminium and throws up aluminium shavings as it passes through the block.

Freeze Moving Tools With A Stroboscopic Camera

April 26, 2026 by 20 Comments

If you take a video of a spinning wheel, you’ll probably notice that the spokes appear to turn more slowly than the wheel is actually rotating, and sometimes in the wrong direction. This is caused by a near match in the frame rate of the camera and the rate of rotation of the wheel – each time the camera captures a frame, the wheel has rotated a spoke into nearly the same position as in the last frame. If you time the exposures carefully, as [Excessive Overkill] did in his latest video, this effect can seemingly freeze moving objects, such as a fan or saw blade.

Most cameras only allow relatively coarse, fixed adjustments to frame rate, making it difficult to synchronize the shutter to an object’s motion. To get around this, [Excessive Overkill] used an industrial camera (previously used in this aimbot), which has fine frame rate control and external triggering. He connected the external trigger to a laser sensor, which detects a piece of retroreflective tape every time it passes by (for example, on one blade of a fan). When the laser sensor sends a signal, it also triggers a powerful LED flash. The flash is so powerful that dark materials create a hum when exposed to it, as pulses quickly heat the material, but each pulse is also so brief that the flash board doesn’t require any cooling.

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Freeze Laser Beams — Sort Of

April 23, 2020 by 5 Comments

They say a picture is worth a thousand words, and by that logic a video must be worth millions. However, from nearly the dawn of photography around 1840, photographers have made fake photographs.  In modern times, Photoshop and Deepfake make you mistrust images and videos. [Action Lab] has a great camera trick in which it looks like he can control the speed of light. You can see the video below.

You probably can guess that he can’t really do it. But he has videos where a real laser beam appears to slowly move across the screen like a laser blaster shot in a movie. You might think you only need to slow down the video speed, but light is really fast, so you probably can’t practically pull that stunt.

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Arduino (and Camera) Take Amazing Pictures

May 17, 2017 by 19 Comments

There’s an old joke where you ask someone what’s the most important thing about comedy. When they get to about the word “important,” you interrupt them and say, “Timing!” Perhaps the same thing can be said for photography. [Ted Kinsman’s] students at the Rochester Institute of Technology would probably agree. They built an Arduino-based rig to do inexpensive stop action photography.

As Arduino projects go, it isn’t very sophisticated. The circuit contains a  sound detection module and an optoisolator. The code would easily fit on a piece of notebook paper. When a loud sound occurs, the Arduino triggers the flash. Simple enough, but the resulting pictures are amazing. It also looks like a lot of fun to destroy perfectly good things in the name of art.

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Slow Motion Frame Will Be The New Magic Mirror

January 24, 2017 by 26 Comments

[Paul] created a frame that uses an Arduino and LEDs to create a slow motion illusion of a delicate item (like a flower or a feather). The effect is striking as you can see in the video below.

[Paul] had seen similar projects (both one-offs and sold as a product), but wanted to do his own take on it. The principle is simple: The device vibrates the objects at one frequency and strobes LEDs at a slightly different frequency (80 and 79.5 Hz, in this case). The difference between the frequencies (the beat frequency) is what your eye perceives as a very slow (0.5 Hz, here) motion.

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