DSLR Trick Lets You Change Focus After Taking The Picture

December 14, 2012 by Mike Szczys 35 Comments

Here’s two photographic takes on the same subject, each with a different depth of focus. [Chaos Collective] came up with a way to make interactive still images that allow a user to adjust the depth of focus by clicking on different objects in the image.

This was inspired by the Lytro camera which uses an array of lenses to take multiple pictures at once. Each of those images has a slightly different depth of focus. The technique used here doesn’t require that you buy one of those $400+ cameras. But it’s not a cheap hack unless you already own a camera that can shoot video and has manual focus.

The technique used by the [Chaos Collective] is to move the camera’s manual focus setting from the nearest to the furthest target while capturing a video. That file can then be processed using their browser-based tool which turns it into an embedded HTML5 image.

Flash Controller Works With Point And Shoot Cameras

November 25, 2012 by Brian Benchoff 7 Comments

Needless to say, there’s a world of difference between the expensive DSLR cameras professional photographers use and the point-and-shoot models carried by commoners. One such difference is the ability to use slave flashes – a second flash set off to the side of the subject for better illumination. Most of these slave flash units are triggered when they see a bright light, or when the on-camera flash goes off. Point and shoot models usually have a ‘pre-flash’ that cause a slave flash to trigger prematurely. [Kerry] built a really neat slave flash that is able to work with these point-and-shoot cameras, and is pretty easy to build as well.

There are two options when it comes to building a flash that can work with a point-and-shoot: First, measure the time between the pre-flash and real flash, and then simply delay the slave flash. This option has a few problems. Even when [Kerry] tested this technique on the same camera, the delay between the flashes were never consistant.

The second option is to simply ignore the pre flash and synchronize with the main flash. This is a little harder, but if done right this technique is nearly foolproof.

[Kerry] ended up building a small circuit out of a 556 timer chip and an LM339n comparator that turns itself ‘on’ just a little bit after it sees the pre flash. From there, the device looks for the main flash and triggers itself whenever it sees another bright source of light.

The finished product works beautifully, and is simple enough for just about anyone to build on a piece of perf board.

Optimizing Your Electronics Projects With A Camera

November 19, 2012 by Brian Benchoff 16 Comments

What do you do when you have a microcontroller you’re trying to optimize? One method is using a debugger, but for AVRs and such that’s not a very common technique. For lower-level electronics projects, it’s nearly impossible, even. [Cnlohr] built a small Minecraft server that listens to in-game redstone circuits, but the performance of his real-world to block-world bridge wasn’t what he hoped. He came up with a pretty clever way of figuring out what was slowing his server down without any special gear at all.

[cnlohr]’s Minecraft server is just a simple AVR microcontroller, Ethernet adapter, and SD card affixed to a beautiful glass PCB. The performance of his server wasn’t what he expected; downloading a largish file from the server resulted in a download rate of about 55kbps, much slower than he expected. He wasn’t quite sure what the hangup was, so he took a camera and with a long exposure time took a very blurry picture.

The Minecraft server has a blue LED to show when the SD card was being accessed. In the picture above, [cnlohr] saw that SD card access was taking far too long, and if he wanted to optimize the code this would be the place to start.

Not bad for a dead-simple method of seeing where the code on your microcontroller project is slowing down.

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Making An Overhead Camera Gantry, Take 2

November 17, 2012 by Brian Benchoff 5 Comments

Last week we saw [Todd]’s solution to getting a tripod out-of-the-way when filming a few DIY videos. It’s an overhead camera gantry that allows him to move a camera around his garage workshop without a tripod getting in the way. This weekend, he’s back with a new and improved version. It’s a vast improvement over his Mk 1 gantry system, and it much simpler to build, to boot.

[Todd]’s new and improved overhead camera gantry builds is a vast improvement on his previous build. In the original build, [Todd] used only one cross piece between the overhead garage door tracks, and the carriage suspending the tripod overhead was extremely clunky.

Version 2 of [Todd]’s camera gantry again makes use of unused garage door tracks to suspend a tripod above his workshop. This time, though, he’s using two rails between these garage door tracks making pushing the tripod around his workshop much easier – even when not pushing it from the middle.

To move the camera across the workspace, [Todd] did away with the square tube between the garage door tracks and used another set of garage door tracks. It’s a beautiful system that moves very, very smoothly between his workbench and welding station, perfect for making a few high-quality DIY videos.

You can check out [Todd]’s build video after the break.

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Nikon WU-1a WiFi Dongle Hacking

November 10, 2012 by Mike Szczys 23 Comments

Here’s a pretty tricky piece of consumer electronics reverse engineering. [Joe Fitz] came across the Nikon WU-1a. It’s a dongle that plugs into a Nikon D3200 camera, producing a WiFi connection which can be picked up and controlled from a smart phone. The app shows you the current image from the viewfinder, allows you to snap the picture, then pulls down the picture afterwards. The problem is that the same functionality for his D800 camera will cost him $1200, when this dongle can be had for $60. That’s a powerful incentive to find a way to use the WU-1a with his camera model. This is more than just rerouting some wires. It involves sniffing the USB traffic and drilling down in the datasheets for the chips used in the hardware. We’re not certain, but he may have even rolled new firmware for the dongle.

Details are a bit scarce right now. Your best bet is to watch the video embedded after the break. There is also a set of slides which [Joe] put together for a talk at this weekend’s BsidesPDX. It will give you a general overview of the process he went through. But he also started a forum thread and we hope to learn much more from that as the conversation gets going.

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Camera Gantry Rides On Garage Door Tracks

November 9, 2012 by Brian Benchoff 4 Comments

For as many garage and workshop videos we feature here on Hackaday, we’re surprised we haven’t seen this sooner.

[Todd] makes a bunch of videos in his garage shop, but using a tripod is a pain; he’s always tripping over his camera setup and it is just generally in the way all the time. His solution was to mount his camera to an overhead gantry, using the unused tracks for his garage door to move the camera around his workshop.

The build started with [Todd] taking his tripod and fabbing a mounting plate for it to be suspended in mid-air. This would leave the camera upside-down, so [Todd] also made a 90 degree bracket with a 1/4-20 bolt to hold the camera in position.

The actual gantry part of the build is fairly clever. First, [Todd] got a piece of square tubing the same length as the distance between his two garage door tracks. He made a truck that rides on six casters for this tube, then mounted this tube on garage door wheels.

The result allow [Todd] to move his camera anywhere within the footprint of his garage door tracks, including over his workbench and welding area. An ingeniously useful build that’s sure to provide a stable platform for his vlog-type thingies.

Vidia after the break.

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Gyrocam Keeps The Horizon Level Even When The Camera Isn’t

October 26, 2012 by Brian Benchoff 44 Comments

[Derek] likes to get a little bit of drivers-eye footage when racing his motorcycle, but there’s an inherent problem with mounting a camera to a moving and tilting platform. When he leans into turns, the camera can’t keep the horizon level. Cinematography and electronics go well together. so [Derek] built a horizon-stabilized camera mount for motorcycle videography.

The build was inspired by footage shot from [Valentino Rossi’s bike in 2010. Of course the professional model costs a small fortune, but [Derek] managed to make his own out of 3D printed parts and a hobby servo.

Based on the Contour Roam camera, [Derek] had a pair of gears printed at Shapeways to fit over the camera and attach to a servo. The electronics are an ATMega32 with a L3G4200D gyroscope. When the ‘micro detects a change in the gyroscope it rotates the servo in the opposite direction, keeping the horizon in the video level.

It’s a very cool build, and judging from the action videos after the break, makes for awesome track footage.

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