A tale of two disposable cameras…
I dropped by a couple of local businesses and ended up with a bag full of used disposable cameras. The cameras are truly disposable; generally tossed or sent back to a company for some amount of recycling. The cameras are chock full of flashy goodness that can be used in quite a number of projects, including high speed photography, of course.
It seems that the disposable camera market is dominated by two manufacturers, Kodak (on left) and Fujifilm (on right). The Quaketronics kit includes a Kodak disposable and, upon disassembly of both, it is abundantly clear why (though apparently coincidental).
Even before cracking the case, there are signs that these are two different beasts. The Fujifilm has a flash switch while the Kodak has a momentary button for charging the flash, thus implying significant differences in the electronics. While opening, the difference in industrial design is immediately obvious. The Kodak’s back is easily popped off by releasing tabs on all four sides. On the other hand, the Fujifilm camera has five or six tiny tabs with an almost-removable-but-not-quite piece over the battery.
Significantly more, including a nice “don’t touch this with your finger” demonstration upon click through…
Now is a good time to offer a warning. Camera flashes do their thing by dumping a massive electrical charge through the flash tube. That charge is buffered in a capacitor. Because of the way the cameras work, it is very likely that the capacitor will be charged upon camera dissassembly. It is critical that you are exceedingly careful in handling the camera. Treat it like an explosive. It is unlikely that it can kill you, but it’ll certainly scare the snot out of you and hurt like hell if you tangle with the charged cap.
Clicking through to the photo page has annotations pointing out the caps. Once the camera is pulled apart, immediately rip out the battery and short out the capacitor. If charged, you will get a loud pop and bright spark. Easy to capture by setting the camera’s exposure to 5 seconds and shorting out the cap in dimly lit room.
Once safely discharged, it is safe to flip the camera over and remove the lens assembly (the Kodak will require that the camera’s front is removed. The Fujifilm comes apart front first) to expose the shutter. The cameras use nearly identical shutter mechanisms. Both of them have a little sliding door with a spring mount to snap the picture. So much for exposure control…
Where they differ is in how the flash is triggered. For the Fujifilm camera, shutter activation trips a leaf switch at the extreme end of its motion. In an effort to reduce parts and manufacturing, Kodak’s design actually uses the metal shutter door as the switch mechanism for the flash. The shutter return spring is actually connected to a piece of metal soldered to the flash controller board and the shutter itself touches a second piece of metal also soldered to the board when the shutter is fully open.
It is now possible to pull the flash boards out entirely. The kodak is the big board on the right. It is actually of a simpler design because it doesn’t have the “automatic charge and shut-off switch” of the Fujifilm. Though more complex, the Fujifilm board is considerably smaller.
In both cases, the flash trigger switch is obvious and easy to connect wires to for the creation of a remote flash unit. When driving them electronically, it is important to figure out the polarity. This is obvious on the Kodak as the board traces are large and easily traced. Not so much with the Fujifilm.
No, really… that capacitor can hurt you.
Given that the units are effectively free by the dozen, I’ll probably not bother figuring out how to wire up the Fujifilm. Instead, I’ll use the Kodak’s for remote flashes and rip the Fujifilm cameras for various one time use experiments. Ben and I had a lot of fun doing exactly that on Friday night….
Of course, you can find schematics and more detailed information on disposable camera electronics. Fuji schematic… Kodak schematic….
