As a boy scout properly acculturated into the DIY philosophy, [Adam] really wanted to get his hands on the new Inventing merit badge. The merit badge required solving a problem, so of course a pinewood derby instant replay system was the obvious solution.

After thinking through a few solution paths like a radio-controlled camera that follows the cars, [Adam] settled on a system that would replay the pinewood derby cars crossing the finish line.  [Adam]‘s father found a cheap and readily available Playstation Eye camera that can record 60fps video for this task. [Adam]  used a laser/photodiode/Arduino setup to detect when a car was crossing the finish line. A bit of Processing code supplied by his father records the relevant 60 frames of video and plays them at 5fps on a projector for the enthralled spectators.

We suspect that a similar setup could be used if [Adam]‘s den wanted to try the rain gutter regatta or oft-forgotten space derby next year. Check out [Adam]‘s instant replay system after the break, or join us in the comments for the inevitable argument over who had the best pinewood derby car.

This lens adapter makes a lot of sense if you’re looking to interface with cameras that don’t have an in-built mounting option. It uses the cap and threaded neck from a soda bottle (translated) to make the lens adjustable and removable.

In the past we’ve seen this hack using a lens cap with a hole drilled in it as the mounting bracket. But that’s only useful if the lens you’ve chosen actually has a cap to use. This method lets you cut the top off of a the soda cap and mount it on the camera. Now each lens can be affixed to the threaded neck of the bottle, allowing for some adjustment of the focal point by screwing the add-on in or out.

Obviously this would work well for macro or fish-eye lenses. But there’s all kinds of other options out there like adding a microscope lens adapter, or actually attaching quality optics to your device.

[Jaroslav's] camera didn’t have a feature to measure the speed of its response in different modes so he figured out his own method. Using the microphone on his webcam he recorded the sound made by the mirror and shutter movements, then used Audacity to analyze the camera’s performance.

When you get right down to it, this is a fantastic idea. Audacity, the open source audio editing suite, has the ability to show each captured audio track next to each other. That makes it easy for you to precisely align the clips, and has in-build time measuring features with fantastic resolution.

He tested a whole bunch of different settings on a Canon EOS600D DSLR camera. In the image above you can see him comparing performance between different ISO settings. He also looks into different brands and sizes of SD storage cards, as well as the time difference when storing raw image data versus JPEG encoded data.

Most people use pacemakers to, you know, keep their heart pumping at a steady rhythm. [David Prutchi] on the other hand has found a pretty novel use for some of the old pacemakers he has in his collection.

We really had no idea that pacemakers had uses outside the world of medicine, but [David] has taken advantage of their reliability in one of his favorite hobbies – high speed photography. In a darkened room, he set up an infrared barrier which feeds its signal to the atrium input of an old pacemaker. The signal is relayed through the ventricular output, which then fires his camera’s flash.

The pacemaker allows [David] to set an “AV” delay, which is the interval between when the atrium input receives an electrical impulse and when that signal is repeated from the ventricular output. This allows him to finely tune how much time elapses from when a drop of milk breaks the IR barrier to when his flash actuates.

We think this is a pretty cool way to reuse an old pacemaker, but check out the shots he has captured and judge for yourself.

Next time you’re waiting in the security line in an airport, why don’t you pull out your smartphone and count all the radiation being emitted by those body scanners and x-rays? There’s an app for that, courtesy of Mr. [Rolf-Dieter Klein].

The app works by blocking all the light coming into a phone’s camera sensor with a piece of tape or plastic. Because high energy radiation will cause artifacts on the CMOS camera sensor inside the phone, radiation will be captured as tiny specks of white light. The title picture for this post was taken from a camera phone at the Helmholtz Research Center in Munich being bathed in 10 Sieverts per hour of Gamma radiation from the decay of Cesium-137.

We have to note that blips of ‘bad data’ from a CMOS camera sensor aren’t unusual. These can come from electrical weirdness in the sensor itself or even the heat from the battery. [Rolf]‘s app takes a reading of the noise floor and subtracts it from the counter. Radioactive decay resulting in Beta particles such as the Potassium-40 in bananas or the Uranium in granite counter tops don’t really register, although [Rolf] did have some success with Potassium chloride and a long measurement time. Still though, it’s a really cool way to turn a phone into a tricorder.

[Fotoopa] keeps churning out new iterations of his laser-triggered camera rig. This is his latest, which he calls the 2011 setup. Regular readers will remember that we just covered a different version back in November; that one was the 2010 rendition. It had two DSLR cameras offset by 90 degrees with mirrors to face forward. This time around he has gone back to the single camera setup which was what he used on the first and second versions seen way back in 2008.

Whew, that’s a lot of links to specialty DSLR hardware. Let’s bring it back to this newest model (the link at the top). The biggest improvement is the shutter delay between when the laser beam is tripped and the image is take. [Fotoopa] reports that he’s managed to reduce that time down to 3.3 milliseconds. This is thanks to an external shutter replacement which improves on the stock shutter’s 52 millisecond delay.

For those that are seeing this for the first time. [Fotoopa] uses this rig to photograph insects in motion. A laser trip wire is responsible for triggering the shutter, and it does so with stunning results!

[L] just finished building this intervalometer and his verbose documentation of the project has a little bit of everything. The fabrication uses common prototyping materials, and simple skills that are easy to master even for the beginner.

The hardware is based around an ATmega8 microcontroller. After snooping around the Internet [L] wanted to see if the voltage divider based focus and shutter commands that are present in some camera remote shutter controls would work for his model. Investigation with a commercial shutter release showed him how it was done, so he incorporated that into his design. When it comes to firmware for the device we really like his explanation of the menu system. There’s a lot of settings and he did a great job of planning the user interface to make them all work on the finished product.

The schematic and board layout were done with Eagle. During the layout process he made choices for easy assembly using strip board, and even walks us through the steps when cutting the traces and adding jumper wires. It’s nicely finished in this clear plastic case and demonstrated in the video after the break.

[Shameel Arafin, Sean McIntyre, and Reid Bingham] really dig rainbows. Going by the moniker the “RainBroz”, the trio built a portable display that can be used to add cool light painting effects to pictures.

The group brings their Rainbow Machine all over the place, including parties, gatherings, and random spots on the street. Anyone is welcome to have their picture taken with the Rainbow machine, and each subject is given a card with a URL on it, so that they can check out their picture whenever they please.

The display consists of addressable RGB LED strips and an Arduino from Adafruit, along with the associated support mechanisms for moving the LEDs. The real magic is carried out by the LPD8806 light painting library, also from Adafruit, which enables the RainBroz to create all sorts of images with little fuss.

As you can see in the video below, the Rainbow Machine seems to get a pretty warm reception from just about everyone, even people grabbed right off the street. It looks simple enough to build, so why not put one together for your next gathering?

For camera fanatics the acquisition of an old camera is a thrilling event. But if you’re going to collect them, you’d better have some repair skills so that you can also use them. [Fernando's] latest find was this Minox 35mm camera. The aperture needed cleaning, and after reassembling the unit he realized the he had not marked the focus ring when taking it apart. This is not a reflex camera, so you can’t look in the view finder to adjust focus. He came up with his own method to get the focus ring calibrated.

The focal point needs to focus on the film. He simulated this plane using some magic tape, which removes easily without leaving a residue. When the shutter is open, you can see the image projected on this translucent surface. He then set up the camera with the lens 90 cm from a bright light bulb. By adjusting the focus to create a sharp image on the temporary screen, he knows the focus is calibrated, and can reset the focus ring to the 0.9m mark.

Need some help developing that exposed film? You could always give the coffee and vitamin C hack a try.

[Duncan Murdock] received a Canon DSLR camera for Christmas and wanted a remote shutter release to go along with it. Since nary a store was open on Christmas, he was pretty much out of luck. Scrounging around in his parts drawer, he found all sorts of goodies waiting to be reused, including a knockoff Wii nunchuck.

He pulled the original cable from the nunchuck and replaced it with an old telephone wire, attaching a 2.5mm plug to the end. The plug goes directly into his camera’s control port, allowing him to trigger the auto focus and shutter mechanisms with the push of a button.

We like the idea of a junk controller being recycled for use in a camera, though we think it has far more potential than being used as a simple wired trigger. If both the nunchuck and camera were fitted with some sort of wireless interface (Bluetooth, IR, etc), we think it would make a great addition to any hobby photographer’s kit.

Here’s a camera mount that moves smoothly along a motorized sled. [Bart Dring] created the system and was surprised by it’s popularity, having received several sales requests from photographers. He originally designed the linear bearing system, called the MakerSlide as an inexpensive alternative to other CNC machine solutions. Allowing a computer to map out timed movements for video shots wasn’t on his radar then, but as you can see in the clip after the break, the MakerSlide does an amazing job at it.

The modular track system makes it easy to attach to a base. In this case, a couple of pieces of acrylic let him support both ends of the track on standard camera tripods. [Bart] mentions the knowledge gap between people who work with CNC milling hardware and photographers as an issue in deciding how to control the system. Since photographers aren’t likely to be proficient in EMC2, he designed a control application with an Arduino. It uses a stepper motor controller shield, and does some fancy math to make sure there is smooth acceleration, etc.

Since most DSLR cameras now have an IR communication port, [Julius] thought it would be a good idea to build an  IR shutter release remote. He has released the plans for two versions; a single sided hand etched one, and a double sided one to have made professionally. He notes that it should have a range of at least 10 meters thanks to the 100mAh Li-Po battery and a reasonably high power IR LED.  You can download the source code as well as the etching mask and eagle files from the wiki page.  He does note that you may have to change the pattern sent to match your camera.

Most of you probably have a webcam sitting around somewhere, and after all the high voltage projects you’ve done using disposable cameras, we bet you have some camera lenses too. You could always do what [Butch] did and combine the lens from the camera with the webcam to do some up close inspection.

This seems like something we’ve seen several times, but we can’t find it in our archive. Such a simple and quick hack looks surprisingly effective in his shots. If you want to see the details, like where he tied into the webcam’s board to power an external LED, you’ll have to download the PDF.

Sure, [Stan] could have bought a nice full-frame DSLR like a Canon 5D or a Nikon D3, but where’s the fun in that when he could build his own digital camera? The build isn’t done yet, but [Stan] did manage to take a few sample pics.

The 14 Megapixel sensor [Stan] found was originally used for benchtop applications. There isn’t any reason it can’t be used for photography, so all that needed to be done was design a camera around this sensor.

[Stan] built his hardware around a DSP, an FPGA and a pair of ADCs, an amazing piece of engineering. Of course building a full-frame digital camera has as much to do with mechanics as electronics, so [Stan] used a 60mm cage system and a 3d-printed nylon enclosure.

Of course, [Stan]‘s camera doesn’t look much like and off-the-shelf DSLR. There’s a reason for this; the sensor in the camera has a rolling shutter, much like the last few iPhones instead of a focal plane shutter. Not a bad piece of work, we only wish there were more build pics.

We suppose they could just trade shoes, but that wouldn’t be a hack. [Timothy] wanted to design a team-building exercise at work, and he figured the best way to get some empathy would be to have people swap eyes. He calls his project eyeSwap and it is supposed to, “put the eye back in team.”

[Tim] found a few CRT viewfinders in a junk box attached small video cameras to each one. During the ‘training phase’ of his team-building exercises, both people playing the game complete a few hand-eye coordination tasks to get a feel for the rig. After the training phase, the inputs are swapped; Alice’s cameras are sent to Bob’s viewfinders and vice versa. The participants then complete the same tasks they did during the training phase.

The tasks aren’t that hard – putting balls into holes, for example – but it does require a huge amount of communication and coordination. eyeSwap reportedly builds trust and empathy towards others, and looks like a lot more fun than a ‘trust fall.’

Check out the video of two people playing eyeSwap after the break.