Femto-photography: Taking Pictures Of Bullets Made Of Light

August 17, 2012 by Mike Szczys 27 Comments

Femto-photography is a term that derives its name from the metric scale’s prefix for one-quadrillionth. When combined with photography this division of time is small enough to see groups of light photons moving. The effect is jaw-dropping. The image seen above shows a ‘light bullet’ travelling through a water-filled soda bottle. It’s part of [Ramesh Raskar’s] TED talk on imaging at 1 trillion frames per second.

The video is something of a lie. We’re not seeing one singular event, but rather a myriad of photographs of discrete events that have been stitched together into a video. But that doesn’t diminish the spectacular ability of the camera to achieve such a minuscule exposure time. In fact, that ability combined with fancy code can do another really amazing thing. It can take a photograph around a corner. A laser pulses light bullets just like the image above, but the beam is bounced off of a surface and the camera captures what light ‘echos’ back. A computer can assemble this and build a representation of what is beyond the camera’s line of sight.

You’ll find the entire talk embedded after the break.

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Raspberry Pi Wedded To A DSLR

August 16, 2012 by Mike Szczys 11 Comments

This is a Raspberry Pi outfitted in a DSLR battery grip. [Dave H] was very interested in the idea of combining a single-board computer with a high-end camera. The size and cost of such a computer was prohibitive until the RPi came along. He managed to fit the board into the broken battery grip he had on hand, and he already has the prototype up and running.

[Dave’s] alterations to the battery grip allow access to the USB, Ethernet, and Composite video ports. Powering the RPi was a bit of a challenge. He tried using an iPhone charger with four AA batteries but that only provided 4.2V. After going back to the drawing board he discovered he could rework the parts that he removed from the grip, using a Cannon 7.2V 1800 mAh battery. So far he can automatically pull images from the Camera and transmit them over a network connection. But since the RPi is running Linux, there’s a whole world of hacks just waiting to be exploited. What comes to mind first is image manipulation software (like ImageMagick) which has a command-line interface.

[Thanks Christian]

Dual PIR Photo Trigger By Crossing The Streams

August 3, 2012 by Mike Szczys 9 Comments

Motion sensing can be quite effective when taking photographs of wildlife. But how can one be sure that the motion was at the center of the frame? A PIR sensor picks up motion in its entire viewing range. It’s not really something that can be aimed. But if you use two PIR sensors you can monitor a focused area for motion.

The trick is to use a logic circuit. By building an AND gate you can trigger based on motion in the area which is overlapped by both of the sensors. In this case the AND gate is built from a voltage divider. The outputs of the PIR sensors are connected above and below the divider’s connection to the photo trigger. Both have a protection diode, and the divider is tuned so that both PIR outputs must come one in order to raise the trigger input above the voltage threshold. So much for never crossing the streams.

[via TriggerTrap]

Building A SkyCam-like Camera Mount

August 3, 2012 by Mike Szczys 19 Comments

With the Olympics on there are a lot of really great camera shots shown during the events. One of the best is the overhead view, which is provided by a camera suspended between cables. It’s not new for the Olympics, SkyCam has been around for over twenty years. What is new is [Dan Royer’s] attempts to build his own aerial camera setup.

He’s not starting from zero with this project. [Dan] has done some really great work with the Drawbot. It’s a two-motor, two-axis plotter which uses CNC to draw on a white board. For this project he combined two Drawbots in order to add a third axis. The image above shows the camera mount suspended between the four strings. He’s been working hard on getting the software ready for this kind of addressing. Along the way he broke the strings a few times because he was too far from the kill switch to stop it in time. But what he’s got is a nice start and we hope to see a more illustrative follow-up soon.

One of the things that SkyCam has going for it is a stabilization system. We wonder if a spinning gyroscope would work as well as it did for that balancing bike.

Atomic Clapperboard

August 2, 2012 by Mike Szczys 13 Comments

Whether you know it as a clapperboard, a slate, slate board, time slate, or by another name, you probably recognize this staple of movie making. It’s a handy way to help synchronize sound with video, and to keep track of clips when it comes time to edit. But this clapperboard is quite a bit more accurate than most. It’s got an atomic clock source for dead-on accuracy.

The project came from the growing availability of Rubidium clock source modules on eBay. They can be had for under $100 and you’ll enjoy accuracy of 0.1 ppm. [Luddite Tech] grabbed one for himself and included it in this build. As you can see in the clip after the break, the contrast of the eight-digit display is adjustable, and shines brightest when the marker is snapped. We’d guess the cable he connects at the beginning of the demo is used to set the initial time reference. After that the in-built WiFi can be used to push the time markers to a computer.

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Never Miss A Roadside Photo-op With An Easy Camera Hack.

August 1, 2012 by Caleb Kraft 31 Comments

When you’re driving for days on the highway, you see some interesting things. If you’re like me, you usually don’t have the time to get your camera out and snap a picture. Especially if it is just a goofy looking car, or an interesting tree or something. This hack will make it really easy to get pictures of sights on the highway by allowing you to snap a picture at the press of a button.

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Reading Punch Cards With An Arduino And Digital Camera

July 30, 2012 by Brian Benchoff 27 Comments

[digitaltrails] wanted the data on a few old IBM 80-column punch cards he had lying around, but didn’t have decades old computer hardware in his garage. He decided to build his own out of LEGO, an Arduino, a digital camera, and a bit of Python.

The hardware portion of [digitaltrails] build includes a crank-operated feed mechanism made entirely out of LEGO. For each turn of the crank, the feed mechanism sends one card down a chute where a photodetector wired into an Arduino tells a camera to take a picture. After that, a servo is activated, sending the card into the ‘already scanned’ bin.

On the software side of the build, [digitatrails] used the Python Imaging Library to scan one row of pixels where each column is expected to be. The software outputs the code and data contained on the 80-column card as well as a very cool ASCII art version of each card.

Considering you just can’t go down to Fry’s and buy an IBM 80-column punch card reader, we’re loving [digitatrails]’ clever way of getting data off an otherwise unreadable storage medium. Check out the video of the card reader in action after the break.

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