The people at [Hobby Robotics] decided to build a trigger circuit for lightning photography. There are more complex ways to do this, but they just used a photo transistor and an Arduino. The Arduino watches the photo transistor’s value and compares it to the previously captured one. If the difference is above a certain threshold, it means a rapid change in the amount of light has occurred, which triggers the shutter. An earlier post covered how to directly control the Canon 30d using an Arduino. All of this works because the shutter lag and code execution together are less than lighting’s 100ms duration.
digital cameras hacks978 Articles
TI-83 Intervalometer
The headline How to Make Time Lapse Video With Your DSLR didn’t really grab us. Honestly, you pay that much for a camera and it can’t do time lapse out of the box? Well, we nearly missed the real story: [Chris Martino] was using a TI-83 to act as the intervalometer for the camera. The calculator has a 2.5mm audio jack for it’s data port and the camera has an identical port for the shutter trigger. The TI-83 runs a program with a FOR loop to act as the timer. When the loop completes it sends data to the port, and the voltage triggers the shutter. The rate isn’t very exact and varies depending on the charge left in the batteries. [Chris] estimated 10000 program iterations ends up being about 26 seconds between pictures. This technique has been tested on 84, 86, and 89 series calculators too. There are a couple example time lapse videos embedded after the break.
Porting CHDK To New Cameras
While researching the CHDK How-To, we came across the team’s instructions for porting the firmware to entirely new cameras. In theory, CHDK should work on any Canon running the DIGIC II or III processor since most of them are running the same VxWorks OS. A dump of the camera’s firmware is required before porting work can begin. On some cameras, the firmware was retrieved using software, but others required a hardware route. Pictured above is a Canon A610 that’s slowly flashing out every bit of its firmware using the built in LED. The photodiode is hooked up to a soundcard where the entire bitstream is recorded. It takes 1-7 hours to read the entire firmware. Once the sound file has been captured, it’s reverted to the original bytes and can then be decompiled with something like IDApro.
How-To: Expand Your Camera With CHDK
As anyone who has lusted over the technical specifications for Canon’s new Digital Rebel XSi knows, the capabilities of the average point and shoot camera are severely limited. Using the CHDK firmware hack, the features of Canon point and shoot cameras can be significantly expanded, allowing for ultra-high speed photography, very long exposures, time lapse photography, and RAW capture. This How-To provides a guide to our experiences using the CHDK firmware, and shows just how easy it is to get more out of a point and shoot than ever thought possible.
Underwater Camera Housings
Underwater cameras can produce some amazing photography, but who wants to pay for housing if you can make something yourself?
This underwater camera housing on Instructables doesn’t require a specific container, allowing you to choose anything you have around the house that’s watertight and large enough to fit your camera. A finger from a glove is added so you can still operated the controls. A similar project uses an insulated water jug, accommodating any camera that fits inside. Neither of these involve any camera mods.
Custom Mounting Manual Minolta/Sony Lenses
We usually get Canon mods, but [polossatik] sent in some interesting Sony/Minolta lens modding work by [Shaocaholica], who’s been really been taking lens modding to a new level of quality. He picked up several old Rokkor F1.2 lenses and swapped parts around to make four decent lenses. Then he had [Pete Ganz] turn down some new mounts on his lathe. Finally, a quick round of epoxy to add a lens id chip activates the on board image stablization and focus confirmation. Be sure to check out the photo build log here.
Simple Digital Camera Spectroscope
[JC Doré] sent in this [english] interesting optics hack. The rubber grips are made from an old mouse pad, the springs for the clip were salvaged from zip drive floppy discs. A pair of old photo slide frames sandwich a diffraction grating slide. (Like this one) This simple mod allows the slide to be mounted to most cell phones, turning them into digital spectrometers.
